01 -
In a medium bowl, combine ricotta cheese, chopped sun-dried tomatoes, chopped spinach, and grated Parmesan cheese. Mix thoroughly and season with salt and black pepper to taste.
02 -
Arrange sourdough bread slices on a clean surface. Spread a layer of ricotta mixture on one side of each slice.
03 -
Sprinkle shredded mozzarella cheese evenly over the filling on half of the bread slices. Top each with a remaining slice, ricotta side in, forming sandwiches.
04 -
Heat a large skillet over medium heat. Add 1 tablespoon olive oil and 1 tablespoon butter. Once butter is melted, place two sandwiches in the skillet.
05 -
Grill sandwiches for 3–4 minutes per side or until bread is golden and cheese is fully melted. Repeat with remaining sandwiches, adding more olive oil and butter as needed.
06 -
Transfer sandwiches to a board and let rest for 1 minute. Slice in half and serve warm.