Instructions

1. Cut the heirloom tomato into ¼-inch-thick slices. Lightly season with salt, if desired, and let sit for about 5 minutes. Gently blot with a paper towel to remove excess moisture.

2. Butter one side of each slice of sourdough. Place two slices, buttered-side down, on a work surface. Top each with a slice of cheddar, half of the shredded mozzarella, several slices of heirloom tomato, another slice of cheddar, and the remaining mozzarella. Season the tomatoes with freshly ground black pepper, if desired. Top with the remaining bread, buttered-side up.

3. Heat a large skillet over medium-low heat. Add the sandwiches and cook for 3 to 4 minutes per side, pressing gently with a spatula, until the sourdough is golden brown and crisp and the cheese is completely melted. Let the sandwiches rest for a minute before slicing. Serve warm.