To make the pesto, combine 2 cups basil, nuts, garlic, Parmesan, and ¼ tsp salt in a food processor. Pulse until finely chopped. With the processor running, slowly drizzle in ⅓ cup olive oil until smooth.

Slice the baguette or ciabatta rolls in half and lightly toast until golden.

Arrange tomato slices on a plate. Drizzle with olive oil and season generously with flaky sea salt and black pepper. Let sit for 5 minutes to enhance the flavor.

Spread pesto on both sides of the bread. Layer mozzarella or burrata, fresh basil leaves, and marinated heirloom tomatoes onto the bread.

Finish with a drizzle of balsamic glaze and an extra pinch of flaky sea salt if desired.

Close the sandwich and serve immediately. Enjoy!