1/3 c. red wine vinegar
1/3 c. salad oil
1 sm. onion, thinly sliced & separated in rings
1 tsp. salt
2 tsp. dried parsley flakes
1 tsp. prepared mustard
1 tbsp. brown sugar

2 (6 oz.) cans mushroom crowns, drained

Simmer 5 to 6 minutes. Chill in a covered bowl several hours, stirring occasionally. Drain. Makes 2 cups or about mushrooms.