Prepare the Bread. Slice your ciabatta, focaccia, or crusty sandwich bread in half. If you want a little extra texture, lightly toast the bread before assembling.
Slice the Mozzarella and Tomatoes. Cut the fresh mozzarella and tomatoes into even slices. This helps create a balanced sandwich with a little of everything in each bite.
Layer the Ingredients. Arrange the mozzarella slices on the bottom half of the bread, followed by the tomato slices and fresh basil leaves.
Season and Add Flavor. Sprinkle the tomatoes with salt and black pepper. Drizzle with olive oil and balsamic glaze, or spread a little pesto onto the bread if using.
Close and Serve. Add the top half of the bread and press gently. Cut the sandwich in half and serve immediately, or toast it briefly in a panini press or skillet if you prefer a warm sandwich.