Wash the mushrooms properly if using fresh mushrooms.
Remove the stems from the mushrooms. Chop the stems finely and keep aside.
Heat the butter in a frying pan.
Fry the onions for two minutes and add the grated cheese, chili garlic paste, finely chopped mushroom stems and chopped coriander. Mix well and allow to cook for two minutes.
Stuff the mushrooms with the above mixture.
Arrange in a flat baking dish. Bake for five minutes before serving.