Mix the yeast with half a glass of lukewarm water.
Mix a good pinch of salt in another glass of water.
Sieve the flour onto a pasturi board and make a well in the middle. Pour the water with the yeast, the salted water and 6 tbsp. Of extra virgin olive oil into the well.
Start mixing and when the ingredients come together, knead for about 10 minutes until you have a smooth, springy soft dough.
Lightly oil a bowl and transfer the dough (it won’t stick to the bowl and it won’t dry); cover with a tea towel and let it rinse for about 2 hours in a warm place without any airstreams.
Knead the dough again, place it on an oiled baking tray and spread it until 1,5 cm thick.
Oil your hands and spread your fingers to make little dimples on the dough. Emulsify the remaining oil with 3 tbsp of water and, with a brush, evenly oil the surface. Let it rinse for 30 minutes covered with a dampened tea towel.
Top the focaccia with some coarsely chopped kosher salt (and rosemary, at your taste).
Pre-heat the oven at 200°C (392°F). Bake at at 200°C (392°F) for the first 20 minutes, then at at 220°C (428°F) for the last 3/4 minutes.