steak fajita casserole garnished with fresh cilantro — Makes: *6 Servings*
Per Serving: *40g Protein | 308 Cal*

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I love sizzling steak fajitas, but making individual fajitas can sometimes just feel like too much work, especially after a long day. That’s why I love this new recipe so much! Creamy, savory, and so delicious, my Creamy Steak Fajita recipe is a brand-new contender for your regular rotation.

Tender, juicy steak, savory peppers and onions, melty cheese, and a creamy sauce make this easy dinner recipe a total hit with the whole family. Even better? Each serving packs in over 40 grams of protein, even though it tastes super cozy and comforting.

Whether you’re cooking for a crowd or just trying to get a dinner on the table that your family will actually like, you’re going to want to give this easy weeknight recipe a try.

Why You’ll Love This Steak Fajita Casserole Recipe

Packed with protein: Each serving gives you about 40g of protein, perfect for those trying to eat more protein each day.
It’s lower in carbs: Serving this fajita casserole with traditional tortillas or tortilla chips will add to the carb count, but without that this casserole is only 9g of carbs per serving. Not too bad for those watching their carb intake!
Super creamy without higher-fat ingredients: This casserole gets its creaminess from the addition of Greek yogurt instead of cream cheese or sour cream, making it more macro-friendly.
Great for families: This dish isn’t too spicy if you make it as the recipe is written, but if you’d like to bump up the heat level, it’s super easy to make it spicier.
Good for meal prepping: If you’re a meal prepper, you’ll definitely want to add this to your “to make” list. It reheats well and will feed you all week long.
Naturally gluten-free: If you can’t tolerate gluten, this one is a-okay for you. Just make sure you check the label on your seasoning packet for any hidden gluten.

dish of finished fajita casserole with tortillas and a fajita on a plate

Ingredients

1½ lbs lean steak (sirloin, flank, or top round), sliced thin against the grain
1 packet store-bought fajita seasoning (I used Siete!)
Cooking spray or light oil
4 bell peppers, thinly sliced
1 large yellow onion, thinly sliced
1 (4 oz) can diced green chiles, very well drained
1 can diced tomatoes, very well drained
1 cup plain Greek yogurt (2% recommended)
2 cups shredded Monterey Jack or Mexican-blend cheese, divided
Juice of ½–1 lime
For garnish: fresh cilantro, green onions, jalapeños or pickled jalapeños
To serve: tortillas or tortilla chips

Instructions

Preheat the oven and prep the baking dish: Turn on and preheat your oven to 375 degrees F. Lightly grease a 9x13-inch casserole dish with cooking spray. Set the dish aside until you’re ready for it.
Sear the steak: Sprinkle the packet of fajita seasoning mix over the sliced steak and toss well to combine. Heat a large skillet over high heat. Add a little bit of oil. When the oil is hot, add the steak in a single layer. Cook for 1 ½-2 minutes per side, until the steak is browned on the outside, but not cooked through. Remove the steak from the skillet and set it aside.
Sauté the veggies: Add the peppers and onions to the same skillet. Cook over medium heat for about 3-4 minutes, or until the veggies have softened slightly and the moisture has evaporated. Stir in the drained green chiles and tomatoes. Cook for another minute or two to let the liquid evaporate and the flavors meld.
Make the creamy sauce: Add the steak back into the skillet, take the pan off the heat and let it cool for 2-3 minutes. Add the Greek yogurt, 1 cup of shredded cheese, and the lime juice and stir well to combine.
Assemble the casserole and bake: Transfer the steak mixture to the prepared baking dish and top with the rest of the cheese. Place the casserole dish in the oven and bake uncovered for about 20-25 minutes, until the casserole bubbles and the cheese gets lightly golden brown.
Garnish and serve: When the casserole is cooked, remove from the oven and let it rest for about 5-10 minutes. Top with minced fresh cilantro and jalapeños or hot sauce if you’d like. Enjoy!

Nutrition Information (Per Serving - Makes 6 Servings)

Calories: 308
Protein: 40g
Carbs: 9g
Fat: 13g

overhead photo of finished fajita casserole garnished with fresh cilantro

Why I Love Using Greek Yogurt in This Recipe

I love using Greek yogurt instead of sour cream or cream cheese because it makes the dish creamy without adding a ton of extra calories, gives us an additional protein boost, and helps the casserole hold together. It’s important to note that 2% is better than fat-free in this recipe because fat-free can separate more than you’d like when baking.

Pro Tips for the Best Steak Fajita Casserole

Make sure you drain the tomatoes and green chiles really well: This will keep your casserole from getting too soggy while baking.
Don’t cover your casserole: Baking your casserole uncovered is another way to prevent excess sogginess because it’ll let the steam escape.
Sear the steak in the skillet: You want that skillet to be hot so it just sears the steak. Cooking it too long in the pan will result in tough, overcooked steak in your finished casserole.
Slice your meat against the grain: This is another way to tenderize the meat and make sure you get the right texture. Slicing with the grain will make it stringy and hard to eat. Definitely not what you’re looking for.

Swaps & Substitutions

Make it dairy-free: Use a thick and creamy plant-based yogurt and opt for dairy-free shredded cheese.
Make a chicken fajita bake: If you’d like to make a chicken fajita casserole instead of this steak version, all you need to do is swap in thinly sliced chicken breast or thighs or shredded leftover chicken. If you're using raw chicken, make sure your chicken is cooked to an internal temperature of 165 degrees F.
Add more fiber: Stir in a can of black beans or pinto beans to the casserole mixture. You could also serve alongside refried beans.
Make it spicy: Add minced jalapeño, pickled jalapeños, a dash of hot sauce, or a pinch of cayenne pepper.
Add extra vegetables: Sauté sliced mushrooms with the fajita veggies, add diced zucchini, or wilt some spinach.
Make your own fajita seasoning: If you'd like, mix up your own blend of spices to use instead or swap in taco seasoning.

How to Serve Your Healthy Fajita Casserole

There are so many ways you can serve this family favorite. Here are a few suggestions:

Roll into warm corn tortillas (you can also use grain-free or flour if you’d like)
Serve over white rice, brown rice, or cauliflower rice
Eat on its own
Use tortilla chips to scoop it up
Add sliced avocado or guacamole on top
Top with pico de gallo

FAQs

You can! Assemble the casserole, cover it with aluminum foil, and store it in the fridge for up to 24 hours before baking. You might need a little bit longer in the oven so that everything’s warmed through and fully cooked.
You might notice that your casserole is a bit watery if you used fat-free yogurt or light sour cream, if you covered the casserole while baking, or if your tomatoes or green chiles weren’t drained well enough to remove that extra liquid before you added them to the veggies.
This casserole reheats great, so it’s an ideal choice for busy weeknights or meal prepping. Simply store leftovers in an airtight container in the fridge and then gently reheat until warmed through.

If you’re craving fajitas but want something easier, creamier, and protein-packed, this Creamy Steak Fajita Casserole checks every box. You’re going to absolutely love it!