Low-Carb Turkey Casserole with Mushrooms, Mozzarella, and Cauliflower Rice
This Low-Carb Turkey Casserole with Mushrooms, Mozzarella, and Cauliflower Rice can be made with turkey or chicken.

Ingredients
- 6 cups chopped cauliflower
- 1 pound Crimini mushrooms, washed and sliced
- 4 cups cooked leftover turkey or chicken
- 1 onion, chopped
- 2 T olive oil, divided
- 1 tsp. dried thyme
- 1 tsp. dried Poultry Seasoning
- salt and fresh-ground black pepper to taste
- 1 cup coarsely grated Mozzarella
- 1 cup sour cream
- 1/2 cup mayo
- 2 T Dijon mustard
- 1/2 tsp. dried thyme
- 1/2 tsp. dried Poultry seasoning
- 1 cup grated Mozzarella
- 1/4 cup coarsely grated Parmesan cheese
Directions
- Spray a large glass or crockery casserole dish with olive oil or non-stick spray. (I used a dish that was 10″ x 13″ but any size that’s close to that will work.)
- Preheat oven to 375F/190C.
- Chop up enough cauliflower to make 6 cups of small cauliflower pieces. (Use frozen cauliflower rice if you prefer, about 3-4 cups.)Then use a food processor with a steel blade to pulse the cauliflower until it’s finely chopped, slightly larger then kernels of rice. (See the recipe for cauliflower rice for more about how to do this.
- You can also chop the cauliflower by grating it on the side of a box grater.)
- Wash the mushrooms and cut into thick half slices.
- Dice the leftover turkey (or chicken) into bite-sized pieces.
- Mix together the sour cream, mayo, Dijon mustard, 1/2 tsp each dried thyme and Poultry seasoning, 1 cup grated Mozzarella, and 1/4 cup Parmesan to make the thick sauce mixture.
- Heat 2 tsp. olive oil in a large non-stick frying pan and saute the mushrooms over medium-high heat until they release their liquid, all liquid evaporates, and mushrooms are starting to brown.
- Put mushrooms in the bottom of the casserole dish.
- Add about 2 tsp. more olive oil and saute the onions over medium-high heat until they are softened and starting to brown.
- Put onions over the mushrooms in the casserole dish.
- Heat another 2 tsp. of olive oil and add the finely-chopped cauliflower.
- Cook over medium-high heat, stirring often, until the cauliflower is starting to soften and barely brown, about 3-4 minutes (or slightly less for frozen cauliflower rice).
- Add the 1 teaspoon each of dried thyme and Poultry Seasoning and cook about 1 minute more.
- Season the cauliflower rice with a little salt and fresh-ground black pepper; then put it into the casserole dish over the mushrooms and onions.
- Put the diced turkey into the casserole dish over the veggies and use a plastic spoon to combine the ingredients right in the dish. (You can do this in a bowl if you prefer, but we were trying to get away without dirtying another dish!)
- Spread the sauce mixture over the top and then use the spoon to gently combine the ingredients with the sauce, until the ingredients are well mixed into the sauce.
- Wipe off the sides of the casserole dish with a paper towel if needed.
- Sprinkle with Mozzarella cheese and bake uncovered until the casserole is starting to bubble and the top is nicely browned, about 40 minutes.
- Let cool about 5 minutes; then cut into 8 servings and eat while hot.