Line the muffin moulds with filo sheets and brush with melted butter. Similarly make three layers of filo sheets in each mould. Bake in a pre heated oven at 200 C for 5 minutes. Heat olive oil in a pan. Add chopped garlic and sliced mushrooms and cook until the mushrooms reduce in size. Add black pepper powder salt, and balsamic vinegar. 7 Mix well and set aside. Allow the moulds to cool and demould the filo sheet cups. Line the filo sheet cups with torn iceberg lettuce leaves and fill the mushroom mixture. Mushroom Cups are ready to serve.