If you’ve been craving comfort food while sticking to a healthy lifestyle, this Low-Carb Mexican Chicken Casserole will absolutely hit the spot. It’s creamy, cheesy, and full of that spicy Mexican flair everyone loves — all while staying keto-friendly and gluten-free.
Inspired by the bold flavors of fajitas, this easy casserole brings together tender shredded chicken, sautéed peppers, onions, and spiced cauliflower rice, all coated in a rich cheese sauce. It’s the kind of meal that disappears fast — even the kids will ask for seconds!
Why You’ll Love This Low-Carb Mexican Chicken Casserole
This dish is pure comfort food — without the carbs. Every bite is loaded with creamy cheese, juicy chicken, and just the right amount of heat. You can throw it together using leftover chicken or even turkey, making it a fantastic weeknight meal that saves both time and money.
Plus, this casserole fits beautifully into keto, Atkins, diabetic, and gluten-free meal plans. It’s hearty enough to be served on its own, yet versatile enough to pair with all your favorite toppings.
The Inspiration Behind This Dish
This recipe was born out of a love for fajita flavors — sizzling peppers, tender chicken, and melty cheese — all baked into a cozy, family-friendly casserole. It’s similar to a low-carb taco casserole but with a unique twist: more fajita-style vegetables and a creamy, spicy cheese layer that binds it all together.
The best part? It’s a clever way to use up leftover chicken or turkey from another meal. If you’ve got cooked meat sitting in the fridge, this recipe turns it into something extraordinary in under an hour.
How This Casserole Comes Together
The base starts with riced cauliflower — a low-carb staple that mimics traditional rice while adding a subtle texture that absorbs all the savory flavors.
It’s layered with sautéed onions and bell peppers, juicy chunks of chicken, and a luscious cheese sauce made with shredded cheese, cream, and spices.
Once everything is assembled, the casserole gets topped with even more cheese and baked until bubbly, golden, and perfectly melted. The smell alone will have everyone heading for the kitchen.
Even though everything is made from scratch, the process is surprisingly simple. Most of the work is done by the oven, giving you plenty of time to tidy up or prep your toppings while it bakes.
What to Serve with This Low-Carb Mexican Chicken Casserole
This dish is a meal in itself — you’ve got protein, veggies, and a starch substitute all in one pan. But if you’d like to add something extra, here are a few perfect companions:
- A fresh green salad with a tangy vinaigrette
- Sliced avocado or a scoop of guacamole
- A dollop of sour cream
- Salsa or pico de gallo for a burst of freshness
- Diced jalapeños for a spicy kick
You can also set up a “topping bar” and let everyone customize their plates with their favorites — a fun and easy idea for family dinners or casual gatherings.
How to Store Leftovers
If you’re lucky enough to have leftovers (which is rare in my kitchen!), you can keep them fresh for up to three days in the refrigerator.
Let the casserole cool completely before covering it tightly with a lid, foil, or plastic wrap. While it’s best enjoyed fresh, it holds up beautifully in the fridge and reheats with all the same creamy texture.
I don’t recommend freezing this dish because the dairy-based sauce can sometimes separate after thawing, which can alter the creamy consistency.
How to Reheat This Keto Chicken Casserole
To bring your leftovers back to life, reheating in the oven is the best option.
- Preheat your oven to 300°F (150°C).
- Remove any lid or plastic wrap and place the casserole (or portion) in an oven-safe dish.
- Heat until it’s hot in the center — the time will vary depending on the size of your serving.
If you’re in a hurry, you can also use the microwave. Reheat in 20–30 second bursts, stirring gently each time until evenly heated.
What If You Don’t Have Leftover Chicken?
No leftovers? No problem! You’ve got options:
- Rotisserie chicken: Grab one from the grocery store and shred it — quick and easy.
- Fresh chicken: Dice raw chicken breasts or tenders into bite-sized pieces. Sauté them in a bit of avocado oil with salt and pepper until golden and cooked through.
- Ground chicken or turkey: Works just as well for a different texture.
Once your chicken is ready, you can use the same pan to cook your onions and peppers — this way, all those flavorful bits left in the pan blend into the veggies for an extra boost of taste.
Creative Ways to Use Leftover Chicken
This casserole isn’t the only delicious way to make the most of leftover poultry. If you’ve got extra cooked chicken or turkey, try transforming it into:
- A Low-Carb Chicken Avocado Salad
- A Creamy Chicken & Veggie Soup
- Or even another baked dish like a Low-Carb Turkey Casserole
Keeping cooked chicken on hand is a total lifesaver for quick, satisfying keto meals.
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Cheesy Low-Carb Mexican Chicken Casserole – A Keto Comfort Food Favorite
- Total Time: 50 min
Description
This Low-Carb Mexican Chicken Casserole combines juicy chicken, spiced cauliflower rice, and melty cheese for the ultimate keto-friendly comfort meal. It’s creamy, flavorful, and perfect for using up leftover chicken — a simple dinner everyone will love.
Ingredients
16 oz (450 g) riced cauliflower
1 medium onion, diced
1 green bell pepper, diced
2 cups cooked shredded chicken (leftover or rotisserie)
1 tbsp avocado oil (or olive oil)
1 tsp chili powder
½ tsp cumin
½ tsp smoked paprika
¼ tsp garlic powder
¼ tsp onion powder
½ tsp salt, or to taste
¼ tsp black pepper
1 cup shredded cheddar cheese
½ cup shredded mozzarella
½ cup cream cheese, softened
¼ cup heavy cream
Optional toppings: sour cream, salsa, jalapeños, avocado, or cilantro
Instructions
-
Preheat the oven to 375°F (190°C) and lightly grease a baking dish.
-
Sauté the veggies:
In a large skillet, heat avocado oil over medium heat. Add diced onion and green pepper, cooking until soft and fragrant (about 4–5 minutes). -
Add the cauliflower rice:
Stir in the riced cauliflower and season with chili powder, cumin, paprika, garlic powder, onion powder, salt, and pepper. Cook for another 3–4 minutes until warmed through. -
Mix in the chicken:
Add shredded chicken to the skillet and combine well. Remove from heat. -
Make the cheese sauce:
In a small saucepan (or microwave-safe bowl), mix cream cheese, heavy cream, and half of the shredded cheese blend. Heat gently until smooth and creamy. -
Assemble the casserole:
Spread the chicken mixture evenly in the baking dish. Pour the cheese sauce over the top, stirring gently to combine. Sprinkle the remaining cheese on top. -
Bake:
Bake uncovered for 25–30 minutes, until bubbly and golden. -
Serve hot with your favorite toppings — salsa, sour cream, or a sprinkle of fresh cilantro.
Notes
- You can replace chicken with cooked turkey or ground chicken for a twist.
- Adjust the spice level with extra chili powder or diced jalapeños.
- For a creamier texture, stir in an extra 2 tablespoons of heavy cream before baking.
- Store leftovers in an airtight container for up to 3 days in the refrigerator.Avoid freezing — the dairy sauce can separate after thawing.
- Prep Time: 20 min
- Cook Time: 30 min
- Method: Baking
- Cuisine: American
