These slow cooker steak fajitas combine pull-apart chuck steak, capsicum and red onion with salsa, Mexican seasoning and fresh lime. They're a low-effort dinner that's particularly useful for meal prep because you can cook one big batch of fajita filling and turn it into rice bowls, tacos, wraps or burritos throughout the week.
I've also learned from making recipes like my slow cooker mexican chicken that Mexican seasoning can lose some of its intensity after hours in a slow cooker. I start this one a little bolder than I would my sheetpan fajita recipe, then finish it with fresh lime to give that extra oomph of flavour.
But, the good thing about slow cooker recipes is that you can use those cheaper cuts of beef like a chuck steak because the longer cooking time softens it - I do this in my slow cooker beef stroganoff as well. While it does fall apart a little bit more than your typical steak fajitas, for meal prep, I actually prefer the pull-apart texture because it reheats without becoming chewy.
TL;DR
- Servings: 8 serves
- Prep time: 15 minutes Cook time: 5 hours (high), 7 hours (low)
- Meal prep: Excellent for meal prep because the beef and vegetables form one versatile base you can pair with rice, tortillas or different toppings during the week.
- Fridge storage: Up to 3-4 days in an airtight container. If serving with rice, store separately or beside.
- Freezer storage: Up to 3 months for best texture. Freeze the fajita filling separately from rice, tortillas and fresh toppings.
- Reheating: Microwave 1 minute intervals (approx. 2 minutes); Stovetop medium heat (approx. 5 minutes)
- Customise: Change the salsa heat, add chillies or jalapenos, bulk it out with black beans and corn, or serve as fajitas, tacos, burritos or rice bowls.
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Why you'll love this recipe
Mexican flavours. Salsa, Mexican seasoning and lime give you plenty of fajita flavour while staying practical for batch cooking.
Versatility. Serve the fajita filling with rice, spoon it into tacos, wrap it into a burrito or change things up throughout the week.
Simple ingredients. Chuck steak, vegetables, salsa and seasoning do most of the work, making this the sort of slow cooker recipe that doesn’t require half the pantry.
Meal prep. The saucy beef reheats without drying out and can be stored as one large batch, so you're not committed to eating the exact same assembled meal several days in a row.
Ingredients
Chuck steak. Chuck is my pick over skirt or other quick-cooking steak because its connective tissue softens during long cooking, giving you tender pull-apart beef without paying extra for steak that's better suited to a hot frying pan.
Salsa. I use medium salsa"even with my very white-girl spice tolerance because I've found the slow cooker softens the heat considerably; use mild or hot if that's more your thing.
Mexican seasoning. I use my homemade taco seasoning because I can adjust the spices individually, including adding a little extra oregano when I want the mixture slightly more herb-forward.
Lime. Cook the zest with the beef, then add the juice at the end so you get a fresher acidic finish after the other flavours have spent several hours cooking.
Capsicum and red onion. These go in from the beginning so they become very tender, absorb the sauce and tuck easily into fajitas or tacos.
Please check the recipe card for full list of ingredients and quantity. See below for substitutions and variations.
Substitutions and variations
Extra veg. Add sturdy vegetables such as mushrooms, potatoes or carrots with the capsicum and onion, but stir canned black beans, corn, peas or beans near the end because they're already cooked and only need enough time to heat through.
Serve with. Spoon the beef fajitas into tortillas or tacos, make burritos, serve with rice for meal prep bowls, or add the filling to nachos with your preferred fresh toppings.
Salsa. Change between mild, medium and hot salsa according to your spice tolerance; in a pinch, use passata or tinned tomatoes with tomato paste.
Spicier. Use hot salsa or add sliced fresh chilli or jalapenos - even some chilli powder or chilli flakes at the end will help bring out a bit more spice.
Different beef. Brisket or another slow-cooking beef (like blade) cut can work (just note they each behave differently so the final texture will be slightly different. I wouldn't substitute an expensive tender steak unless that's simply what you already have.
How to make slow cooker steak fajitas
Step 1: Season the chuck steak with salt and pepper, then sear it in a hot searing slow cooker for approximately 3 minutes, turning to brown the outside. If your slow cooker doesn't sear, use a frying pan over high heat for approximately 1 minute per side.
Step 2: Add the sliced capsicum and red onions, Mexican seasoning, salsa and lime zest. Mix well so the salsa and seasoning coat the beef and vegetables.
Step 3: Cover and cook on high for approximately 5 hours or low for approximately 7 hours. The chuck steak is ready when it separates easily with two forks.
Note - Don't panic if there is more liquid in the slow cooker than you'd expect from stovetop beef fajitas. The beef and vegetables release liquid while cooking and the filling will thicken somewhat as it cools; if you want it thicker immediately, remove the lid for approximately the final 30 minutes and allow some of the moisture to evaporate.
Step 4: Add approximately 2 tablespoon lime juice over the finished fajita mixture, taste and adjust the salt, pepper or Mexican seasoning if needed.
Note - Taste after adding the lime rather than before. Acidity can bring back some of the contrast that disappears during a long cook, so something that initially tastes slightly flat may simply need the fresh lime rather than another large spoonful of seasoning.
Lauren's Top Tips
Start slightly bolder with the seasoning. I've found Mexican flavours mellow noticeably in slow cooker recipes, so I use a well-seasoned salsa and don't begin with an overly timid spice mix.
Start slightly bolder with the seasoning. I've found Mexican flavours mellow noticeably in slow cooker recipes, so I use a well-seasoned salsa and don't begin with an overly timid spice mix.
Recommended Equipment
A searing slow cooker is particularly useful because you can brown the chuck in the same bowl and avoid creating another pan to wash. For leftovers, I prefer glass meal prep containers because the red salsa can stain plastic.
Meal prepping slow cooker steak fajitas
These slow cooker steak fajitas are particularly practical for meal prep because the main batch already contains your protein from the chuck steak and vegetables from the capsicum and onion, while the carbohydrate can change depending on how you serve it. Add rice for a meal prep bowl one day, use tortillas the next or turn the leftovers into a burrito later in the week.
Storing
Allow the slow cooker steak fajitas to cool before transferring them to airtight containers and refrigerate promptly. Keep for up to 3-4 days in the fridge.
This is also one of those meal preps where I don't think assembling every portion in advance is necessarily the best option. The filling itself stores well, so leaving some in a large container gives you flexibility without adding any meaningful work at dinner time.
If you'd rather have completely assembled meals ready to grab, rice is the easiest option. Keep the rice and fajita mixture on opposite sides of the container rather than spooning the wet mixture directly over the top. The filling releases quite a lot of sauce, which can continue soaking into the rice while it's refrigerated.
Keep tortillas and crunchy or fresh toppings such as lettuce, avocado, coriander or sour cream completely separate and add those after reheating.
Lauren's Meal Prep Tip
I usually portion enough meals for the next few days, then freeze the rest immediately rather than waiting until the end of the week to decide I won't get through it. Future-you gets an emergency dinner and nothing has spent unnecessary days sitting in the fridge.
Reheating
For the microwave, transfer one serving to a microwave-safe dish and heat for 1 minute, stir, then continue heating in 1-minute intervals until steaming hot throughout, usually around 2 minutes depending on your microwave and portion size.
On the stovetop, place the fajita filling into a saucepan or frying pan over medium heat and cook for approximately 5 minutes, stirring regularly, until heated through and steaming. If the sauce has thickened significantly in the fridge, add only a small splash of water rather than automatically adding more salsa.
Freezing
Slow cooker steak fajitas freeze particularly well because the chuck is surrounded by sauce, which helps protect it from drying out when it is reheated. Freeze the fajita mixture separately from rice, tortillas and fresh toppings so you can decide later whether that portion becomes a fajita, burrito or rice bowl. I like freezing individual portions in 1-cup Souper Cubes.
The fajita mixture can be quite moist so I do recommend freezing separately to the rice. It is quite good in the freezer because of the sauciness. Also recommend storing separately from the rice because that gives you more flexibility if you want to serve it with something else. I do this in my 1 cup souper cubes which is good for a single serve (once added to something).
For best quality, use within approximately 3 months.
You can defrost the fajita mixture overnight in the refrigerator or use the microwave's defrost function from frozen. Once loosened, heat it in 1-minute intervals, stirring between each interval, until steaming hot throughout.
If you want more meal prep information, check out my Meal Prep for Beginners post and my Meal Prep Basics E-Book.
FAQs
Beef, capsicum and onion all release moisture while cooking. Leave the lid off for the final 30 minutes if you want the sauce thicker, and remember that it will also thicken somewhat as it cools.
Beef, capsicum and onion all release moisture while cooking. Leave the lid off for the final 30 minutes if you want the sauce thicker, and remember that it will also thicken somewhat as it cools.
Beef, capsicum and onion all release moisture while cooking. Leave the lid off for the final 30 minutes if you want the sauce thicker, and remember that it will also thicken somewhat as it cools.
Other easy slow cooker recipes you'll like
Or, you can have a browse through my slow cooker meal preps for more delicious eats.
Recipe
Slow Cooker Steak Fajitas
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Equipment
Ingredients
- 1 kg chuck steak, see note 1
- 3 capsicum / bell peppers
- 2 red onions
- 3 tablespoon Mexican seasoning, see note 2
- 1 cup salsa, mild recommended, see note 3
- 1 lime, juice and zest. approx.1tbsp zest, 1.5tbsp juice
- Salt and pepper, to taste
Serve with:
- 2 ½ cups rice, yields approx.8 cups cooked, see "serve with" note for other serving suggestions
Instructions
Preparing
- Slice the 3 capsicum / bell peppers and 2 red onions. Zest and juice the 1 lime, keeping the approx. 1 tablespoon zest and 1.5 tablespoon juice separate
- Season the 1 kg chuck steak with Salt and pepper on both sides. Slice into thin strips
Cooking
- Heat a searing slow cooker and sear the chuck steak for approximately 3 minutes, turning to brown the outside. If your slow cooker doesn't have a searing function, use a frying pan over high heat for approximately 1 minute per side, then transfer the beef to the slow cooker. You're only browning the surface here, not cooking the steak through.
- Add the capsicum, red onions, 3 tbsp Mexican seasoning, 1 cup salsa, lime zest to the slow cooker. Mix well so the beef and vegetables are evenly coated in the salsa and seasoning.
- Cover and cook on HIGH for approximately 5 hours or LOW for approximately 7 hours. The chuck steak is ready when it is very tender and separates easily when pressed or pulled apart with two forks.Note - The fajita mixture may look quite saucy when first cooked because the beef and vegetables release moisture. For a thicker filling, remove the lid for the final 30 minutes of cooking to allow some of the liquid to evaporate.
- If serving or storing with 2 ½ cups rice, prepare it according to packet instructions or you can follow my tips and tricks.
- Add the lime juice once cooking is complete, then taste and adjust with additional salt, pepper or Mexican seasoning if needed. Add the lime before adding extra seasoning, as the acidity can lift flavours that have mellowed during slow cooking.
- Serve on top of the rice or on tortillas, in burritos or even on top of pasta.
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