Preheat oven to 400ºF
Bring a large pot of water to a boil. Add in potatoes and boil 7-10 minutes or until almost fork tender. Then add the corn and boil 3 minutes. Drain.
In large bowl combine potatoes, corn, shrimp, sausage, 2 lemons and onion.
Mix melted butter, oil, garlic and seasoning. Pour mixture over shrimp and other ingredients. Toss until evenly coated.
Transfer shrimp boil ingredients to 2 large greased, rimmed baking sheets. Spread in an even layer. Sprinkle with smoked paprika (optional)
Bake 8-10 minutes or until shrimp are almost cooked though. Broil on high 2-3 minutes until shrimp are pink on the outside and white/opaque on the inside.
Serve with extra melted butter, fresh parsley, salt, lemons and crusty bread.