Step 1: Get your pan heating up over medium-high heat. While it's warming, grab your peeled and deveined shrimp. Give them a little sprinkle of salt and pepper.
Step 2: Melt about 1 tablespoon of your butter in the hot pan. Toss in your minced garlic and cook for just about 30 seconds until it's fragrant – don't let it burn!
Step 3: Add your seasoned shrimp to the pan with the garlic butter. Sauté them, stirring occasionally, for about 3-4 minutes. They'll turn pink and opaque when they're cooked through. Once they're done, take them out of the pan and set them aside on a plate.
Step 4: Now, let's prepare the bread! Brush the remaining melted butter onto one side of each of your four bread slices. This is going to be the outside of your sandwich. Sprinkle the minced garlic evenly over the buttered sides.
Step 5: Flip two slices of bread over so the unbuttered side is facing up. Layer half of the mozzarella cheese and half of the Parmesan cheese on each of these two slices.
Step 6: Evenly distribute your delicious garlic-sautéed shrimp over the cheese layers on those two slices.
Step 7: Top the shrimp with the rest of the mozzarella and Parmesan cheese.
Step 8: Carefully place the other two slices of bread on top, buttered, garlic-y side UP. Your sandwiches are assembled and ready for grilling!
Step 9: Lower the heat on your pan to medium. Place the assembled sandwiches into the pan. Press down gently with a spatula to help them make good contact with the pan.
Step 10: Grill for about 4-5 minutes per side, or until the bread is golden brown and crispy, and the cheese is completely melted and gooey. Keep an eye on them to make sure they don't burn!
Step 11: Once they're perfect, remove from the pan, slice in half (if you dare!), and sprinkle with fresh chopped parsley if you have it. Serve immediately and enjoy every single bite!