Pour warm water in a bowl and add the sourdough starter. Mix with a dough whisk until the sourdough starter dissolves.

Add 10 grams of fast acting yeast.

Add the flour little by little until your ingredients are well combined.

Cover with a towel and let sit on the counter for about 20 minutes.

After 20 minutes add 25 grams of vegetable shortening and 10 grams of salt. Mix in the bowl to incorporate.

Take the dough out of the bowl and start kneading by hand for about 15 minutes or until your dough is no longer sticking to your table and it is soft and elastic.

Place it in a greased bowl and cover with a plastic wrap. Let it proof in a warm place at 86 degrees (30 C) until it doubles in size.

Stretch your dough one last time to help develop more gluten and tension, then make a ball out of the dough and let it rest for about 10 minutes.

Divide your dough into 8 equal pieces. Stretch and fold each piece of dough and roll it into a ball.

Cover your dough balls with a towel and let them rest on the counter for 10 minutes.

To shape your bolillos, stretch the dough and fold one side towards the middle pressing it down firmly with your fingers then fold down the other side and repeat the process.

Press the ends of the dough firmly and flip the dough around. Roll the dough pressing down on the ends to make the dough thinner at the edges.

Place the rolls on a prepared baking sheet. Cover with a towel and let proof in a warm place for about 1 hour.

After 1 hour sprinkle some flour on the bolillo rolls and score with a dough lame making a single cut in the middle of the roll.

Pour a cup of water on a preheated tray at 420 degrees F (215 C) to create some steam in your oven and place the bolillo rolls in the oven.

Spray more water on the dough and the hot oven to create more steam.

Bake for about 20 minutes.

Take your bolillo rolls out of the oven and allow them to cool for 10 minutes before slicing.