Slice each ciabatta roll or baguette in half horizontally. If you prefer a warm, slightly crisp sandwich, spread about 1/2 tablespoon softened butter on each cut side. Heat a skillet or griddle over medium heat and toast the buttered sides 1–2 minutes until golden and slightly crisp. Alternatively, toast under a broiler for 1–2 minutes, watching carefully to avoid burning.

Prepare tomatoes

Wash and dry the tomatoes. Slice them into 1/4-inch (6 mm) thick rounds. Place slices on a paper towel-lined plate and sprinkle with about 1/2 teaspoon of the salt to draw out excess moisture; let sit 5 minutes, then pat dry gently to avoid soggy bread.

Prepare mozzarella

Drain fresh mozzarella and slice into 1/4-inch (6 mm) rounds to match the tomato slices. If the mozzarella is packed in liquid, pat slices lightly with paper towel to remove excess moisture.

Assemble sandwiches

On the bottom half of each toasted roll, brush about 1/2 tablespoon of extra-virgin olive oil. Layer tomato slices evenly (about 3–4 slices per sandwich), then top with mozzarella slices. Tuck several fresh basil leaves between the cheese and tomato and a few on top (about 6–8 leaves per sandwich, or to taste). Sprinkle remaining 1/2 teaspoon salt and the black pepper evenly across the sandwiches.

Finish and serve

Drizzle about 1/2 tablespoon extra-virgin olive oil and 1/2 tablespoon balsamic glaze over the cheese and tomato layers on each sandwich. If using, rub the cut side of the top bread with the optional garlic clove before placing it on the sandwich for a subtle garlic aroma. Close sandwiches, press gently, slice in half if desired, and serve immediately.

Notes

Adjust balsamic glaze and salt to taste. For a lighter version, omit butter used for toasting and reduce olive oil to 1 tablespoon brushed across both halves. To make ahead for picnics, keep components separate (toasted bread, sliced tomato, mozzarella, basil) and assemble just before eating to prevent sogginess.