If you use small mushrooms, clean and stem, leaving whole.
Medium mushrooms, halve. Large mushrooms, sliced into 3-4 pieces
Mix vinegar, garlic, olive oil and parsley in a plastic container large enough to hold the mushrooms.
Mix all ingredients together and place in the refrigerator for 3 days. Stir once or twice to circulate the mushrooms. Can be served with small toasts, crackers or on toothpicks a an appetizer, or on salads to add a bit of zing.