My husband makes the most delicious mushroom sauce. This is really easy.
Start by adding some butter in a pot. Add in some chopped mushrooms. Fry in the butter till soft. Add in about a cup of milk or more. Place heat on high and turn down.
Mix a few teaspoons of cornflour with some water, and add to the milk and mushroom mixture. Stir until the sauce thickens. Set aside and serve with your favourite meat or chips.