Preheat your oven to 375°F.
Line a large baking sheet with a silicone baking mat, parchment or aluminum foil.
Arrange the shrimp, sausage, potatoes, corn, mushrooms, and onion pieces in a single layer on your prepared baking sheet.
1 pound raw jumbo shrimp, 12 ounces smoked sausage, 1 pound small yellow potatoes, 2 to 3 corn cobs, 8 ounces white mushrooms, 1 medium sweet onion
Melt the butter in a microwave-safe bowl.
16 tablespoons salted butter
Stir in the Old Bay seasoning, garlic and chopped parsley.
1½ tablespoons Old Bay seasoning, 2 teaspoons minced garlic, 2 tablespoons chopped fresh parsley
Use a basting brush to generously coat all of the meat and veggies in the butter mixture.
Bake in the oven for 20-25 minutes or until the potatoes are soft.
Serve over grits or with a salad if desired, and enjoy!