Put the olives in a bowl, along with the olive oil, lemon zest and thyme. Cover the bowl and marinate for 3-4 hours or a night.

Put 500 g of flour in a bowl and make a well in the middle. Stir in a small bowl the yeast with 100 ml of water to a smooth mass, scoop in the well and add the rest of the water. Knead until a sticky dough that has something away from a batter. Stir with the mixer to obtain a homogeneous mass. Cover with a damp cloth and allow to rise at normal room temperature for 3 to 4 hours, until it has about three times the original size. Check from time to time that the dough does not stick to the tea towel. In that case, sprinkle some flour over the dough.

Knead the risen dough. Strain the olives, remove the lemon zest and keep the oil. Mix oil and salt through the dough and gradually knead in the remaining flour, until a soft sticky dough is formed. Divide it in half and put 1 serving in another bowl. Mix half of the olives through each portion. Cover with a damp cloth and let rise again to the double size, about 1 hour.

Bake for 30 minutes in a preheated oven (220 degrees) until the loaves are brown and hollow. Leave to cool on a grid.