Bari-Style Focaccia

Method

1. In a large bowl, combine 2 parts all-purpose flour (00) and 1 part semolina flour. Add one boiled and mashed potato and mix.
2. Crumble about 20 g of fresh yeast and add 1 tablespoon of sugar to the flour mixture.
3. Add cold water (about 70% hydration, i.e., 700 g water per 1 kg flour) and begin mixing by hand until a shaggy dough forms.
4. Transfer the dough to a work surface and knead vigorously until the dough becomes smooth and elastic (develops a 'rope').
5. Dissolve a generous amount of salt in a little water and knead it into the dough.
6. Cover the dough with a cloth and let it rest for 10 minutes.
7. Add a generous amount of extra virgin olive oil and give the dough a few folds to incorporate.
8. Place the dough in a lightly oiled bowl, cover, and let rise at room temperature until doubled in size (about 2.5 hours).
9. Generously oil two baking trays.
10. Divide the dough in half and give each piece a couple of folds, then place directly onto the oiled trays.
11. Drizzle more olive oil on top and cover loosely with plastic wrap; let rise for another 30 minutes.
12. Preheat the oven to 200°C (400°F).
13. Wet your hands and press dimples into the dough with your fingertips.
14. Spread crushed peeled tomatoes (or fresh tomato when in season) evenly over the surface.
15. Dot with black olives.
16. Bake for about 30 minutes, rotating the trays halfway through, until the focaccia is golden brown and crispy on the bottom.
17. Let cool slightly on a wire rack, then sprinkle with dried oregano.
18. Serve warm.