Preheat the oven to 375 degrees. Heat the olive oil over medium-high heat in a large skillet. Add the onion and cook for 3-4 minutes until beginning to soften. Add the garlic and cook for 30-60 seconds until fragrant. Add the ground turkey, Italian seasoning, salt, and pepper. Cook for 6-8 minutes until turkey is fully cooked, breaking it up as it cooks. Add the spinach and tomatoes to the pan and cook for 1-2 minutes until wilted. Drain any excess liquid from the pan. The more liquid you drain, the less watery the casserole will be.
Spray a 9 X 13 casserole dish with cooking spray. Gently warm the cauliflower rice in the microwave. Combine warm cauliflower rice with Greek yogurt, cream cheese, and parmesan cheese in the bottom of the dish. The cream cheese should melt into the warmed rice.