Cook chicken in olive oil, seasoning to taste. Remove once cooked, and fry mushrooms in oil. Set aside. To make the sauce: Melt butter and cook the garlic. Add flour and cook till it thickens. Add broth, cream, milk, Parmesan, garlic powder, pepper and salt. Add spinach and simmer it wilts. Add chicken and mushrooms to the sauce. Serve over pasta or rice.