Focaccia Sandwich with Prosciutto and Pesto

In a large bowl, mix wheat flour, salt, and sugar. Add the dry yeast to the lukewarm water and let it stand for five minutes until small bubbles form on the surface. Pour the yeast water into the flour, add one tablespoon of olive oil, and stir to form a very sticky, thin dough. Carefully cover the bowl with cling film and place it in the refrigerator for 24 hours. During this time, the dough should double or triple in volume and be full of air bubbles.

Prepare a baking sheet (approx. 40x30 cm) and generously grease it with 2 tablespoons of olive oil. Place the risen dough onto the sheet and spread it evenly to the corners with your fingers. Cover again with cling film and let it rise for another 2-3 hours at room temperature. Once the focaccia has risen perfectly, preheat the oven to 220 °C. Drizzle the dough evenly with the remaining olive oil. Press indentations into the dough with lightly oiled fingers. Sprinkle the focaccia with a little sea salt, place it in the hot oven, and bake for approx. 25-30 minutes until golden brown. The finished focaccia should be full of bubbles, nicely crispy, and soft inside.

Cut a piece from the cooled focaccia and halve it lengthwise. Spread both halves with pesto. On one half, place a handful of arugula, prosciutto slices, sliced mozzarella, and basil leaves. Cover with the second half. For easier serving, wrap in baking paper, cut in half, and enjoy immediately.