All the sizzling flavors of chicken fajitas come together in this cheesy, bubbling Keto Fajita Casserole.
There’s nothing I love more than turning a skillet favorite into a hearty casserole that feeds a crowd. Fajitas are a weeknight classic, but with all that chopping and sizzling at the stovetop, they can keep you on your feet longer than you’d like. This keto fajita casserole brings all those same bold Tex-Mex flavors into one dish that bakes up hot, bubbly, and ready to scoop.
What makes this casserole sing is the mix of spice-rubbed chicken, sweet peppers, and tender cauliflower rice, all bound together with layers of queso and Monterey Jack cheese. That queso melts right down into the chicken and veggies, giving every bite that creamy, gooey Tex-Mex flavor you usually only get at a restaurant. Monterey Jack adds the perfect stretchy finish, giving you golden, bubbling cheese on top that just begs to be pulled up with your fork.
This is the kind of meal I turn to on busy nights because it’s a one-pan wonder—protein, vegetables, and big flavor all in one dish. The cauliflower rice makes it hearty without being heavy, the peppers bring brightness and a little sweetness, and the spice blend ties it all together with warmth. By the time it comes out of the oven, your kitchen smells like a fiesta, and you’ve got dinner that’s both keto-friendly and soul-satisfying.
Great keto add-ins
One of the things I love most about casseroles is how easy they are to customize, and this fajita casserole is no exception. Want to kick up the heat? Toss in some sliced jalapeños or a handful of pepper jack cheese for a spicy twist. If you’re after a smoky depth, stir in a few spoonfuls of fire-roasted tomatoes—they melt right into the queso and add a rich, charred sweetness. For extra creaminess, a dollop of sour cream swirled in before baking takes it to the next level. And don’t forget fresh toppings—avocado slices, chopped cilantro, or a squeeze of lime over each serving brighten everything up and give the dish that irresistible, restaurant-style finish.
How do I store leftovers?
If you’re lucky enough to have leftovers of this, store them in an airtight container in the fridge for up to 4 days. For longer storage, portion the casserole into freezer-safe containers and freeze for up to 2 months. To reheat, thaw overnight in the fridge if frozen, then warm gently in the oven at 350°F until heated through. A quick zap in the microwave works too, but the oven will bring back that cheesy, bubbly topping.
Similar recipes to try
If you love this cheesy, flavor-packed casserole, you’ll want to try a few more PepperPorch favorites. This Keto White Chicken Chili simmers with creamy broth and green chilies for a comforting bowlful of Tex-Mex flavor. For another hearty casserole, Keto Supreme Pizza Casserole layers in gooey cheese, zesty sauce, and all your favorite pizza toppings—without the crust. And for a Mexican-inspired twist, Keto Ground Beef Mexican Casserole combines spiced beef, cauliflower rice, and melted cheese for a dinner that’s bold, satisfying, and perfect for weeknights.
Keto Fajita Casserole
Ingredients
- 2 pounds chicken breasts boneless and skinless (3 to 4 large breasts)
- 1 1/2 teaspoons salt
- 1/4 teaspoon chili powder
- 1 teaspoon garlic powder
- 1 teaspoon cumin
- 2 tablespoons butter divided (or oil, for frying)
- 4 1/2 ounces chopped orange bell pepper
- 4 1/2 ounces chopped red bell pepper
- 2 1/2 ounces chopped red onion
- 2 cups cauliflower rice frozen or fresh
- 8 tablespoons store-bought queso not melted
- 1 cup shredded Monterey Jack cheese
- Cilantro optional
Instructions
- Preheat oven to 375°F.
- Cut chicken breasts into 1-inch pieces. In a small bowl, combine the salt and spices. Season the chicken with half of the seasoning.
- In a large skillet, heat half of the butter (or oil). Once hot, add half of the chicken. Cook 3 to 4 minutes until browned. They do not have to be cooked through as they will finish cooking in the oven. Transfer to a large bowl and repeat with remaining chicken.
- Add the peppers, onions, and cauliflower rice to the bowl with the chicken. Season with the remaining spices and toss to coat.
- Add half of the mixture to a medium sized casserole dish. Add half of the queso to the top of the mixture. Repeat once more with remaining mixture and queso.
- Top the casserole with the shredded Monterey Jack cheese.
- Bake uncovered for 25 minutes. Let the casserole rest 5 to 10 minutes before serving.
- Garnish with fresh cilantro, if desired.
Delicious! I prepared everything in the morning so that dinner was quick and easy to toss together. I chopped veggies, and shredded cauliflower, placing them in an airtight container. I also sautéed and seasoned the chopped chicken before placing it in a separate airtight container. Instead of using a jar of queso, I made Velveta and RioTel queso dip the night before.
Love the idea of using homemade queso, I bet it made it even more amazing!