Melt the butter in a large skillet pan. Add the mushrooms and sauté until caramelized, about four minutes. Add the spinach and garlic and stir until the spinach has wilted. Stir in the chicken.
Meanwhile cook the ravioli according to the package instructions. In a small saucepan, stir the milk, cream and Parmesan cheese until slightly thickened. Add salt and fresh ground pepper to taste.
Then add the ravioli and the cream sauce to the mushrooms and spinach mixture and stir to coat all ingredients.