Pour the 375g lukewarm water into a large mixing bowl. Stir in the sugar and active starter, then add the flour and mix until no dry flour remains. Cover with a dry tea towel and rest for 30 minutes.

Add the salt followed by the remaining water and work the salt mix into the dough by squeezing the dough through your fingers and folding it over. Cover again.

Every 30 minutes, come back to the dough and complete a set of Stretch & Fold with a total of four sets. After the last set, cover and rest once more for 30 minutes.

Line a large oven dish (32cm x 25cm x 5cm) with baking paper and drizzle with 2 tbsp of extra virgin olive oil.

Gently place the dough into the dish and carefully stretch it out. Don’t force it or you might deflate the dough. If it doesn’t stretch out easily, let the dough relax for another 10 minutes and try again. Cover with cling film and refrigerate for 14 hours.

When you’re ready to bake, pre-heat the oven to 220°C (200°C fan) [428F] and take the dough out of the fridge.

Once the oven is hot, drizzle the remaining olive oil over the top of the dough and spread it out. With your fingers, press dimples into the dough. You can press all the way down to the bottom of the dish, but don’t deflate any of the larger air bubbles that might have formed overnight.

Sprinkle over the rosemary and the sea salt flakes, then bake for 35 minutes or until golden brown on top.