Focaccia sandwich

In a large bowl, mix all-purpose flour, salt, and sugar. Pour dried yeast into lukewarm water and let it sit for five minutes; small bubbles should appear on its surface. Pour the bubbly water into the flour, add a tablespoon of olive oil, and mix until a very sticky, loose dough forms. Carefully cover the bowl with plastic wrap and place it in the refrigerator for 24 hours. During this time, the dough should double or triple in volume and be full of bubbles.

Prepare a baking sheet approximately 40x30 cm and grease it thoroughly with 2 tablespoons of oil. Transfer the risen dough to the baking sheet and spread it with your fingers to the edges, forming an even layer. Cover again with plastic wrap and let it rise for another 2-3 hours at room temperature. Once the focaccia has risen perfectly, preheat the oven to 220 C° and evenly drizzle the remaining olive oil over the dough. Lightly oil your fingers and press them into the dough to create dimples. Sprinkle the dimpled dough with a little flaky salt, place it in the hot oven, and bake until golden brown, which takes approximately 25-30 minutes. The resulting focaccia should be full of bubbles, beautifully crispy, and tender.

Cut a piece from the cooled, baked focaccia and slice it lengthwise in half. Spread both halves with pesto. On one half, add a handful of arugula, slices of prosciutto, sliced mozzarella, and basil leaves. Cover with the other half and wrap in baking paper for easier serving. Cut the sandwich in half and serve immediately.