Chef Carol Shipman's Deep Dark Mushrooms
1 cup (250 ml) butter or margarine ( I only use butter )
1+1/2 cups (375 ml) onion diced fine
2 lbs. (900 g) mushrooms cut in half
1 cup (250 ml) brown sugar well packed
4 tsp (20 ml) Worcestershire sauce
4 tsp (20 ml) prepared mustard
1 tsp (5 ml) Salt
1/2 tsp (2 ml) Pepper
Melt butter in frying pan. Add onion. Saut until soft stirring
often. Add remaining ingredients. Stir to combine and heat.