Begin by patting the fresh mozzarella dry with a paper towel to remove excess moisture, ensuring a perfectly gooey filling. Spread a generous layer of butter on one side of each slice of thick-cut sourdough bread.

In a skillet over medium-low heat, place one slice of sourdough butter-side down. Layer the mozzarella slices on top, followed by a spread of basil pesto. If desired, add sun-dried tomatoes and cooked bacon for extra flavor. Cap it with another slice of mozzarella, then top with the second slice of sourdough, ensuring the buttered side is facing up.

Heat the skillet gently, letting the Sourdough Pesto Grilled Cheese sizzle. Cook for about 3–4 minutes, until the bottom slice of bread turns a rich, golden brown. Keep the heat low to avoid burning while achieving the perfect melt.

Using a spatula, carefully flip the sandwich over when the bottom is crisp and golden. Allow the second side to cook for an additional 3–4 minutes, until both sides are toasted to a delightful brown and the cheese is fully melted and oozy.

Once both sides are beautifully golden, remove the sandwich from the skillet. Allow it to cool for a minute before cutting it in half. Enjoy your crispy, cheesy bliss warm and fresh!