Slow cooker steak fajitas is an easy, flavorful recipe that uses only a handful of ingredients: beef, onions, bell peppers, diced tomatoes (or salsa), and fajita seasoning. It fills the house with delicious aromas while it cooks and makes a simple weeknight meal. Instructions for making these fajitas in an Instant Pot are included below.
Ingredients For Slow Cooker Steak Fajitas
- Beef (sirloin or flank steak, thinly sliced)
- Fajita seasoning (store-bought or homemade blend)
- Bell peppers (sliced)
- Onions (sliced)
- Diced tomatoes with juices or salsa
How To Make Steak Fajitas In The Slow Cooker
Slow cooker method
- Add the sliced beef, bell peppers, onions, diced tomatoes (or salsa), and fajita seasoning to the slow cooker. Stir to combine so the seasoning coats everything evenly.
- Cook on HIGH for 2–3 hours or LOW for 4–6 hours, until the beef is tender and the vegetables are soft. Taste and adjust seasoning before serving.
Instant Pot / Pressure Cooker method
- Select Sauté on the Instant Pot. Add a tablespoon of oil and brown the beef for 2–4 minutes, then remove and set aside. Drain excess grease if needed.
- Add the sliced onions and bell peppers and sauté 3–5 minutes until slightly softened. Pour in 1/4 cup beef broth or water and deglaze the pot, scraping up any browned bits from the bottom.
- Return the browned beef to the pot, add diced tomatoes (or salsa) and the fajita seasoning, and stir to combine.
- Close the lid, seal the valve, and cook on HIGH pressure for 9 minutes. When the cook time ends, perform a quick release, stir, and serve.
FAQs & Tips
What are fajitas?
Fajitas are a Tex‑Mex favorite made of seasoned, cooked meat served with sautéed onions and bell peppers. Traditionally they are grilled, but slow cooker and pressure cooker versions capture the same bold flavors with less hands‑on time.
What type of beef should you use?
Two pounds of sirloin or flank steak works well. You can also use skirt steak, flat iron, chuck roast, rump, or even stew meat—slow cooking tenderizes tougher cuts. If you prefer, swap the beef for chicken, pork, or turkey breast; the method and flavors remain the same.
Can you use different vegetables?
The recipe calls for two large bell peppers and one large onion. Use any combination of bell pepper colors you like. Red, yellow, green, or orange peppers all work, and red, yellow, or white onions are fine—choose based on taste and appearance.
How do you serve this?
Serve fajitas in flour or corn tortillas, over rice, or in lettuce wraps for a low‑carb option. They also make a great filling for burritos or enchiladas. Popular toppings include shredded cheese, guacamole, salsa, sour cream, cilantro, and lime wedges.
How do you store leftovers?
Store leftover fajitas in an airtight container in the refrigerator for up to 4 days. Reheat gently on the stovetop or in the microwave.
What size slow cooker did you use?
A 6‑quart slow cooker works well for this amount of ingredients. An Instant Pot of similar capacity is suitable for the pressure cooker method.
Homemade Fajita Seasoning
- 2 tablespoons chili powder
- 1 tablespoon ground cumin
- 1 1/2 teaspoons salt
- 1 teaspoon black pepper
- 1 teaspoon dried oregano
- 1 teaspoon paprika
- 1/2 teaspoon garlic powder
- 1/2 teaspoon onion powder
Recipe Details
- Author: Shannon Epstein
- Prep Time: 10 minutes
- Cook Time: 2–3 hours (slow cooker) or 9 minutes high pressure (Instant Pot) plus prep
- Total Time: Approximately 3 hours 10 minutes (slow cooker)
- Yield: About 6 servings
Nutrition (per serving, approximate)
- Calories: 242
- Sugar: 2.4 g
- Sodium: 317 mg
- Fat: 8.1 g
- Saturated Fat: 3.2 g
- Carbohydrates: 7.7 g
- Fiber: 2 g
- Protein: 33.8 g
- Cholesterol: 90.7 mg
More Mexican-Inspired Recipes
- Chicken Fajitas
- Enchilada Tri‑Tip
- Salsa
- Salsa Verde Beef
