I think stuffed mushrooms should always be vegetarian. These have a nice kick to them with the garlic and cayenne. They are straightforward to make, and once in the freezer, make a fast appetizer on the fly.
Adapted from Annie's Eats
24 whole fresh button mushrooms
3-4 cloves garlic, coarsely chopped
2 tsp. vegetable oil
8 oz. cream cheese, softened
¼ cup grated Parmesan cheese
¼ tsp. pepper
¼ tsp. onion powder
¼ tsp. cayenne pepper
Bread crumbs and minced fresh herbs, for garnish (optional)
Preheat the oven to 350° F. Lightly grease a baking sheet with cooking spray. Clean mushrooms with a dry paper towel. Carefully remove the stems from the mushroom caps, setting the caps aside for later. Add about 20 of the stems to the bowl of a food processor. Add the garlic to the food processor as well, and pulse in brief bursts until them mushroom stems and garlic are finely chopped.
Heat the oil in a large skillet over high heat. Add the chopped mushroom stems and garlic and cook on medium high heat until all the moisture has disappeared, about 5-7 minutes. Lower the heat to medium-low. Stir in the cream cheese, Parmesan cheese and spices. Stir together until the mixture is smooth and creamy; remove from the heat. Don't linger or it will get too dry. Using a small spoon, fill each mushroom cap with a generous amount of filling. Arrange the mushroom caps on the prepared baking sheet. Place about 1/2 of cup of breadcrumbs on a plate, and pick the mushrooms up and dunk the filling in the breadcrumbs. You can freeze them at this point if you like- freeze on a cookie sheet for 10 minutes, then put in a ziplock bag. Bake for 20 minutes or until the mushrooms are hot and liquid starts to form under the caps. Transfer to a serving platter, garnish with fresh herbs if using and serve immediately.