Wash the mushroom and remove the stem of it. Chop the stem finely
In a bowl mix together one tablespoon olive oil, vinegar, garlic paste and salt.
Apply this mixture on the mushrooms and set it aside for half an hour
Take one tablespoon olive oil in a microwave bowl, add chopped mushroom stems and onions and cook on microwave HIGH for two minutes.
Add breadcrumbs, salt and black pepper powder and mix. Stuff this mixture into the mushrooms.
Put the stuffed mushrooms in the microwave and cook on HIGH for four minutes. Sprinkle mozzarella cheese on top and microwave for thirty seconds.