Heat olive oil in a large skillet over medium-high heat. Add the onion and celery and sauté, stirring frequently, until the vegetables are soft, approximately 4-5 minutes.
Add the mushrooms, ground turkey, Italian seasoning, red pepper flakes (optional), garlic powder, and onion powder to the skillet. Season with salt and pepper to taste. Cook, stirring frequently until the turkey is no longer pink and the mushrooms start to release their juices, approximately 5-7 minutes.
Reduce heat to medium and add chicken broth. Simmer for 2-3 minutes or until heated through. Add a spoonful of the hot liquid to the heavy whipping cream to temper it before adding it to the skillet as well. Stir to combine and simmer for another 1-2 minutes.
Add frozen riced cauliflower and 1/2 cup of the shredded cheese to skillet and stir to combine. Cook for 1-2 minutes, or until cauliflower is heated through and cheese is completely melted.
To serve, top each bowl with remaining cheese (2 tbsp per bowl) and fresh parsley.
Notes
If you don't like a lot of heat, reduce or eliminate the red pepper flakes. If you love heat, maintain or increase the called-for amount.