Fajitas are always a fun meal, and this Keto Chicken Fajita Casserole packs all the flavors with the ease of a casserole. Perfect for weeknights since you can do all the prep-work ahead of time. It is delicious on its own, but perhaps even more so when served with a dollop of sour cream and a few avocado slices.

Fajitas make a regular appearance on my dinner table, and it is a flavor profile that never gets old.
Traditional fajitas - like these Keto Steak Fajitas - are always delicious, but sometimes I want something that is easier to make ahead of time. And sometimes I am craving a cheesy casserole.
This Keto Fajita Chicken Casserole is easily one of my top-5 favorite casserole recipes. The first time I tested the recipe I wasn't feeling well and went to bed before having any. When I woke up, I was shocked to find the entire thing gone.
(I have two teen boys who are over 6 feet tall, so I am not sure why I was so shocked.)
When I tested it again, I understood why it was so quick to disappear. Give it a try, and I think that you will too.
Ingredients for Low Carb Chicken Fajita Casserole
- Avocado Oil - Avocado oil is my go-to oil because it is keto-friendly AND safe at high heat. If you are going to cook in olive oil, I recommend lowering the heat to medium and increasing the length of time you are cooking to make sure the oil doesn’t go beyond its smoke point.
- Lime Juice - I used fresh squeezed, but you can use bottled if you like.
- Keto Taco Seasoning - I make my own. If you want to purchase taco seasoning, make sure you read the labels. Many contain sugar and other ingredients that you may wish to avoid.
- Sea Salt - I used fine pink sea salt. As always, salt is such a matter of personal preference, so adjust the amount you use to your tastes.
- Boneless Skinless Chicken - You can use breasts or thighs. I’ve made it with both, and it works well either way.
- Bell Peppers - For presentation, I like a mixture of colors.
- Onion - I used a large yellow onion, but whatever you have on hand is good.
- Cream Cheese - Make sure you cube it before adding it to the casserole to make it easier to incorporate.
- Cheddar Cheese - Monterey Jack or Pepper Jack are also great options.
What Do You Serve With Keto Fajita Casserole?
With meat and veggies, this delicious casserole is a meal by itself! It works fabulous with a side of Cilantro Lime Cauliflower Rice or Cabbage Rice. Sometimes I like to wrap leftovers up in a Keto Almond Flour Tortilla. For a simple side, a green salad is also lovely.
Can This Recipe Be Made Ahead?
Yes. This recipe can be made up to two days ahead of time and baked just before serving. Leftovers can be stored in a sealed container in the refrigerator for up to four days.
Reheating
This recipe can be reheated in the microwave, but I prefer the texture when it is reheated in the oven or in a skillet.
How to Make Keto Chicken Fajita Casserole
First, start by marinating the chicken. Combine the oil, lime juice, taco seasoning, and salt in a bowl. Place the chicken in a shallow dish (or zip-top bag) and pour the marinade over. Marinate for up to 4 hours.
Next, preheat the oven and spray your baking dish.
Heat a skillet to medium-high and add the chicken. The oil that clings to the chicken from the marinade should be enough to prevent sticking, but you can add additional oil if you need to. Cook until the chicken is browned, and then remove from the skillet.
Add the vegetables to the skillet and cook until tender.
Reduce the heat and return the chicken to the skillet. Add the cream cheese and taco seasoning and stir until combined.
Transfer to the baking dish and top with the shredded cheese. Bake for 30 minutes.
Keto Chicken Fajita Casserole
Equipment
- 9 x 9 Casserole Dish
Ingredients
- ¼ cup avocado oil
- 2 tablespoons lime juice
- 3 tablespoon keto taco seasoning or fajita seasoning, divided
- ½ teaspoon sea salt
- 1 ½ pounds boneless skinless chicken cut into strips
- 2 bell pepper seeded and sliced
- 1 large onion sliced
- 8 ounces cream cheese softened and cubed
- 8 ounces shredded cheddar
Instructions
- Combine the avocado oil, lime juice, 2 tablespoons of taco seasoning, and salt in a small bowl. Place the chicken in a shallow dish or zip-top bag and pour the marinade over. Marinate for at least 30 minutes or up to 4 hours.
- Preheat the oven to 350 degrees. Spray a 9 x 9 baking dish with cooking spray.
- Heat a large skillet to medium-high heat. Add chicken and cook for 4 to 6 minutes, stirring halfway through until browned. Transfer to a bowl.
- Add the vegetables, and cook until they are crisp-tender, about 5 minutes. (You can add additional oil if the pan is too dry.)
- Add the chicken back to the skillet and reduce heat to medium-low. Add cream cheese and remaining 1 tablespoon of taco seasoning. Stir until melted.
- Transfer to the prepared baking dish. Top with cheese and bake for 30 minutes.
Leave a Reply