Cheesy Keto Chicken Casserole

Name: Cheesy Keto Chicken Casserole
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Ingredients: 4 boneless skinless chicken breasts (8 ounces each; 32 ounces total of raw chicken breasts); Avocado oil spray; ½ teaspoon Diamond Crystal kosher salt; ¼ teaspoon black pepper; ¼ cup mayonnaise (1/3 cup for a creamier casserole); ¼ cup sour cream (1/3 cup for a creamier casserole); 1 tablespoon Dijon mustard; 1 tablespoon fresh garlic (minced); ½ teaspoon Diamond Crystal kosher salt; ¼ teaspoon black pepper; ½ teaspoon dried thyme; ½ teaspoon paprika; ¼ teaspoon cayenne pepper; 1 cup cheddar (sharp, shredded, divided); ¼ cup scallions (sliced, green parts only); ¼ cup bacon bits (room temperature)

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A simple one-dish meal, this keto chicken casserole is easy to assemble and practically bakes itself. Ready in about 40 minutes, it's the ultimate weeknight dinner. And if you happen to have any leftovers, they're great, too!

Keto chicken casserole is served in a white baking dish.

Casseroles make life easy. You throw a few ingredients into a baking dish, bake, and voila - dinner is ready! This delicious casserole is keto, filling, and easy to make. If you have precooked chicken, it's ready in just a few minutes! But even if you need to cook the chicken first, this recipe is fast and easy.

Ingredients

Here's an overview of the ingredients needed for this recipe. The exact measurements are included in the recipe card below.

For cooking the chicken: Chicken breasts, oil, salt, and pepper.

Ingredients for baking chicken for casserole.

Creamy sauce: Mayonnaise (I prefer mayo made with avocado oil), sour cream, Dijon mustard, garlic, spices, and shredded cheddar.

Topping: Scallions and bacon bits.

Scallions and bacon bits for topping keto chicken casserole.

Variations

You can season the chicken breasts with additional spices. I often add ½ teaspoon of garlic powder and ½ teaspoon of paprika.
If you'd like, you can very lightly steam small broccoli florets and mix them into the casserole before the final stage of baking, making it a complete meal. If you do, I suggest you increase the mayonnaise and sour cream to ⅓ cup each.
You can use pre-cooked chicken such as rotisserie chicken in this recipe. Be sure to remove the skin.
While I usually use chicken breast, it's fine to use boneless chicken thighs.

Instructions

Scroll down to the recipe card for detailed directions. Here are the basic steps for making this recipe:

Cook the chicken and cube it. You can bake the chicken, broil the chicken, or use this recipe for poached chicken.

Four cooked chicken breasts on a baking sheet.

Mix the chicken cubes with a creamy homemade sauce. Transfer the mixture to a baking dish and top it with shredded cheese.

The casserole was topped with cheese and is ready to be baked.

Bake the casserole until hot and bubbly. Before serving, sprinkle scallions and bacon bits on top for extra flavor and a gorgeous presentation.

Expert Tip

This casserole is just creamy enough for my taste, and my family likes it this way, too. However, reader feedback over the years has taught me that some people want it creamier. If you'd like your casserole to be extra creamy, I suggest you increase the mayonnaise and sour cream to ⅓ cup each.

Recipe FAQs

Can I put raw chicken in a casserole?

You could if the casserole will be baked for long enough that the chicken is cooked through. But to be on the safe side, I prefer to precook the chicken and then add it to the casserole. In addition, raw chicken will release liquids as it cooks, making the dish watery.

Can you make a casserole without a starchy ingredient?

Absolutely. Although starch is one of the components of a classic casserole, I make low-carb casseroles all the time without any starch, and they come out wonderfully flavorful.

Can I make this recipe without mayonnaise?

Sure. Simply omit the mayonnaise and double the amount of sour cream. It won't be as good - mayonnaise adds extra creaminess and flavor. But it will still be very good.

Serving Suggestions

I usually serve this casserole with a vegetable to round out the meal. Since I bake the casserole in a 450°F oven, I like to serve it with a vegetable that can be cooked in the same love, such as roasted peppers, roasted broccoli, or roasted eggplant.

Alternatively, I serve this casserole with a veggie I can quickly steam or pan-fry, such as steamed broccoli, sauteed spinach, or spicy green beans.

Storing Leftovers

You can keep the leftovers in a sealed container in the fridge for about 3 days. Gently reheat them, covered, in the microwave at 50% power.

However, if you've used pre-cooked chicken that has already spent a couple of days in the fridge, you should take that into account when deciding how long you can keep the leftovers.