In a mixing bowl, combine the warm water, sugar, and yeast. Stir gently and let it sit for about 5-10 minutes until frothy. This step activates the yeast, ensuring your focaccia rises properly.

Add the flour, salt, and olive oil to the yeast mixture. Mix until a sticky dough forms. This dough will be wetter than typical bread dough, which helps create a light and airy focaccia.

Knead the dough on a floured surface for about 5 minutes until smooth. If the dough is too sticky, add a little more flour as needed.

Place the dough in a greased bowl, cover it with plastic wrap, and let it rise in a warm place for about 1 hour, or until doubled in size.

Preheat your oven to 425°F (220°C).

Once the dough has risen, punch it down to release the air. Transfer it to a greased baking sheet and stretch it out to fit the sheet. Use your fingers to create dimples all over the surface of the dough.

Drizzle a little olive oil over the top and sprinkle with coarse sea salt. This adds flavor and helps create a crispy crust.

Bake in the preheated oven for 20-25 minutes, or until golden brown. The focaccia should sound hollow when tapped on the bottom.

Once the focaccia is baked, let it cool for a few minutes before slicing it in half horizontally.

Layer the fresh mozzarella, basil leaves, tomato slices, and roasted red peppers on the bottom half of the focaccia.

Drizzle with balsamic glaze for added flavor, then place the top half of the focaccia back on.

Cut the sandwich into individual portions and serve immediately. Enjoy your delicious focaccia sandwich!