1. Prepare Your Bread and Butter: Lay out your sourdough bread slices on a clean surface. Generously butter one side of each slice. This buttered side will be the exterior of your sandwich, ensuring a beautiful golden-brown crust.

2. Assemble the First Layer of Cheese: Place a slice of provolone cheese on the unbuttered side of four of the sourdough slices. This will be the bottom layer of your sandwiches.

3. Add Tomato and Basil: Arrange a few slices of fresh tomato over the cheese, then scatter a generous amount of fresh basil leaves on top of the tomatoes. Season lightly with salt and freshly ground black pepper.

4. Layer More Cheese: Place another slice of provolone cheese directly over the basil and tomatoes. This second layer of cheese acts as a “glue,” helping to hold all the fillings in place and ensuring an extra-cheesy bite.

5. Complete the Sandwich: Top each assembled sandwich with the remaining four slices of sourdough bread, buttered-side up. Gently press down on each sandwich to secure the fillings.

6. Grill to Golden Perfection: Heat a large non-stick skillet or griddle over medium heat. Once hot, carefully place the sandwiches in the pan. Cook for 4-6 minutes per side, or until the bread is golden brown and crispy, and the cheese is completely melted and gooey. You may need to cook in batches to avoid overcrowding the pan.

7. Serve Immediately: Once grilled, remove the sandwiches from the pan. For easier eating, you can slice them in half diagonally. Serve hot and enjoy the warm, tangy, and fresh flavors.