Preheat your oven to 375°F (190°C).
In a mixing bowl, combine the butter, minced garlic, and chopped parsley. Melt the butter until fully liquefied, then stir in the garlic and parsley.
Add the shrimp to the bowl and toss them in the garlic butter mixture until fully coated. Allow marinating for a few minutes.
Carefully remove the stems from the mushrooms. Fill each mushroom cap with the shrimp mixture, packing it gently.
Sprinkle mozzarella cheese generously over each stuffed mushroom.
Place the stuffed mushrooms in a baking dish and bake for 15-20 minutes, until the shrimp are opaque and the cheese is melted.
Let cool for a minute before serving warm.
