Preheat oven to 400°F
Fry bacon and garlic in a pan. Start frying the bacon first then when bacon is almost done add the garlic. If you add them at the same time the garlic will burn.
In a mixing bowl mix cream cheese, bacon with garlic, half the shredded cheese then the salt and pepper
Put filling in a piping bag then fill each mushroom. Then top with remaining cheese and put in oven for 10 minutes.