01 -
Heat a skillet or griddle over medium heat until ready to toast bread evenly without burning.
02 -
Spread softened butter evenly on one side of each slice of sourdough bread to ensure a golden, crisp crust.
03 -
In a bowl, combine ricotta, mozzarella, and Parmesan cheeses until well mixed for a creamy, meltable filling.
04 -
Place two slices of bread buttered side down on the skillet. Evenly spread cheese mixture over them, then layer with chopped sun-dried tomatoes and fresh spinach leaves. Top with remaining bread slices, buttered side up.
05 -
Cook each sandwich for 3 to 4 minutes per side over medium heat, allowing bread to become golden and cheese to melt thoroughly without flipping too soon.
06 -
Remove sandwiches from skillet and let rest briefly before cutting in half to allow cheese to set and prevent spilling.