Combine the yeast, water, sugar, flour and half the olive oil.
Mix into a soft dough. Leave in a warm place (70°C) until doubled in size.
Add extra flour, water, salt and remaining olive oil and mix to re-form dough. Cover loosely with oiled cling film, to double again in size.
Turn out onto a baking paper lined tray, shape loaves to approx 20cm x 10cm wide. Press in olives and rosemary, and sprinkle with sea salt.
Bake in a preheated oven at 200°C for 30 minutes.