Preheat to 350 degrees. Lay a stick of butter onto a shallow baking sheet (lined with foil or not). Place in oven until melted, about 5 minutes. Spread lemon slices and shrimp in a single layer. Sprinkle Italian seasoning on top. Bake for 10 - 15 minutes, depending on the size of your shrimp (10 minutes was perfect for our large shrimp).