Ingredients:
In a suacepan, saute the onion in oil and butter until transparant.
Add the mushrooms and cook for 2 minutes. Add the tomatoes, salt and pepper. Cover and simmer for 20-30 minutes.
Add the vinegar, parsley and garlic and mix well. Cover and simmer for 10 minutes.
Chill several hours or overnight. To serve, spoon onto slice of French bread.