Using a large bowl, dissolve the sourdough starter in the warm water (it shouldn't be very hot).

Add most of the flour, the salt and whatever spice you have chosen (if you like). Knead well and add as much flour as is necessary to make a dough that doesn't stick to your hands. Take care to not add too much flour because the bread will be very firm.

Knead for an additional 10'-15' minutes.

Set aside a piece of the dough to use as a starter for the next time you make bread. Cover the bowl with a clean towel and leave in a warm place (during winter, next to the fireplace or a slightly preheated oven, but make sure that it is not on) for 8-12 hours until it doubles in size.

Shape your dough into loaves and place in respective trays which you have brushed lightly with oil. Score the top with a knife and brush with a little water (at this point you can sprinkle with sesame seeds and press them a bit with your hand). Set them aside to rise once more.

Bake in a preheated oven at 200°C, for about 40' (depending on the oven and the size of the bread).