1. In a large bowl, combine the ground chicken, breadcrumbs, egg, Parmesan, garlic, salt, pepper, and thyme. Mix until the ingredients are just combined, being careful not to overmix. Form the mixture into 1-inch meatballs.

2. Heat the olive oil in a large skillet over medium heat. Add the meatballs and cook, turning occasionally, until they are browned on all sides and cooked through, about 6-8 minutes. Remove the meatballs from the skillet and set them aside.

3. In the same skillet, melt the butter over medium heat. Add the sliced mushrooms and cook, stirring occasionally, until they are golden brown and tender, about 5-7 minutes. Stir in the minced garlic and cook for an additional minute.

4. Pour in the heavy cream and chicken broth. Stir in the Parmesan, salt, and pepper. Bring the mixture to a simmer and let it cook for 3-4 minutes, or until the sauce has thickened slightly.

5. Return the seared meatballs to the skillet and spoon the creamy mushroom sauce over them. Simmer the dish for 5 minutes, allowing the flavors to meld and the meatballs to heat through.

6. Sprinkle the Creamy Mushroom Chicken Meatballs with freshly chopped parsley. Serve the dish hot, over mashed potatoes, rice, or your favorite pasta for a truly satisfying meal.