Make space in the middle of the flour and add the salt, yeast, sugar, and warm water. Combine until a sticky dough is formed.
Turn out the dough onto a lightly floured surface. Then knead the dough for 10 minutes.
Allow the dough to rise in a warm place for 1 hour.
Add the finely chopped serrano chili, then knead the dough again for 2 minutes.
Split into approximately 18 large balls or 24 smaller ones.
Place on a non-stick baking tray, then add a few rosemary leaves to each one.
Cook in the oven for 18-20 minutes or until turning slightly golden. Monitor the bread closely as the bread balls can be browned earlier than this timing.