Toss & coat shrimp with 1/2 cube melted butter, minced garlic, & juice & zest of lemon.
Refrigerate until ready to cook.
Preheat broiler & cook onions in 1/2 cube melted butter.
Add shrimp & broil 2 min,
Stir & cook 2 min more.
Add mushrooms & additional butter if desired.
Sprinkle with garlic powder, salt , pepper & paprika.
Broil until mushrooms are cooked & shrimp is done.
Serve with wild rice pilaf.