Step 1: Prepare the Garlic Butter

1. In a small bowl, mix softened butter, minced garlic, and parsley. Set aside.

Step 2: Cook the Shrimp

1. Heat olive oil in a skillet over medium heat.
2. Add the shrimp, season with salt and pepper, and cook for 2-3 minutes per side until pink and fully cooked.
3. Remove from the skillet and chop the shrimp into bite-sized pieces.

Step 3: Assemble the Sandwiches

1. Spread a generous layer of garlic butter on one side of each bread slice.
2. Place the buttered side down on a cutting board or plate.
3. Sprinkle a layer of mozzarella and cheddar cheese on the unbuttered side of 4 slices.
4. Distribute the cooked shrimp evenly over the cheese.
5. Top with the remaining bread slices, buttered side up.

Step 4: Cook the Grilled Cheese

1. Heat a skillet or griddle over medium heat.
2. Place the assembled sandwiches on the skillet and cook for 3-4 minutes on one side, pressing gently with a spatula for even toasting.
3. Flip and cook for another 3-4 minutes until the bread is golden brown and the cheese is melted.

Step 5: Serve

1. Remove the sandwiches from the skillet and let them cool slightly.
2. Slice each sandwich in half and serve with marinara sauce for dipping, if desired.