Tip the flour into a large mixing bowl. Mix the yeast into one side of the flour, and the fine salt into the other side. Then mix everything together, this initial separation prevents the salt from killing the yeast.
Make a well in the middle of the flour and add the olive oil and 350-400ml lukewarm water, adding it gradually until you have a slightly sticky dough (you may not need all the water).
Oil the work surface with a tablespoon of olive oil and tip the dough onto it, scraping around the sides of the bowl.
Knead for 5-10 minutes until your dough is soft and less sticky. Put the dough into a clean bowl or on an oiled tray, cover with a tea towel and leave to prove for 1 hour or until doubled in size.
Oil a rectangle, shallow tin (25 x 35cm). Tip the dough onto the work surface, then stretch it to fill the tin. Cover with a tea towel and leave to prove for another 35-45 minutes.
Heat the oven to 220C/200C fan/Gas 7. Press your fingers into the dough to make dimples. Lightly chop the rosemary and pop into a small mixing bowl, add the olive oil and 1 tablespoon water, mix.
Drizzle this over the surface of the dough, pushing your fingertips into top to re-make the dimples. Sprinkle with the sea salt flakes over the bread.
Bake for 20 minutes until golden. Whilst the bread is still hot, drizzle over 1-2 tablespoons olive oil. Cut into squares and serve warm or cold with extra olive oil if you like.
500g strong white bread flour
7g fast action yeast
2 teaspoons fine sea salt
2 tablespoons olive oil – plus extra for the tin and for kneading
To Finish
1 small bunch rosemary
3 tablespoons olive oil
1 teaspoon flaky sea salt
After baking
1-2 tablespoons olive oil