Preheat oven to 350 degrees.

Squeeze lemon juice into a big cup and add the garlic.

Add the shrimp to the cup and let stand for 5-10 minutes.

Cut stems from mushrooms.

Place mushrooms upside down on a lightly oiled baking pan.

Bake for 10 minutes or until tender.

Remove from oven and add 1 shrimp into each mushroom.

Bake for additional 15 minutes.

Garnish with green onion.

Serve and enjoy.