Preheat your oven to 375°F (190°C) and lightly grease a baking dish

Heat olive oil in a large skillet over medium heat

Add diced onion, celery, and mushrooms, cooking for 5–6 minutes until softened

Stir in minced garlic and cook for 30 seconds until fragrant

Add cauliflower rice and sauté for 3–4 minutes to reduce moisture

Add cooked turkey to the skillet and mix everything evenly

Season with thyme, paprika, salt, and pepper

In a mixing bowl, whisk together heavy cream, eggs, and sour cream until smooth

Stir in half of the mozzarella and cheddar cheese into the creamy mixture

Combine the creamy mixture with the turkey mixture and stir well

Transfer everything into the prepared baking dish

Spread evenly using a spatula

Sprinkle remaining mozzarella, cheddar, and parmesan cheese over the top

Bake for 25–30 minutes until the casserole is set and cheese is melted

Broil for 2–3 minutes for a golden, slightly crispy top

Remove from oven and let rest for 5–10 minutes

Garnish with parsley if desired

Slice into portions and serve warm