Heat 2 tbsp oil in a medium skillet over medium. Add the mushrooms and 1/4 tsp salt, and cook, stirring occasionally, until softened, 5 to 6 minutes. Remove from heat. Stir in vinegar, garlic, oregano, bay, crushed red pepper, 1/4 tsp salt and 1 tbsp oil. Cool slightly.Advertisement
Transfer to a quart-size jar and seal. Refrigerate up to 5 days. Serve at room temperature. Makes 2 cups.