In a large mason jar, start by adding the warm water, the salt, the dry yeast powder, mix well.
Close the jar and let the mixture ferment for 10 minutes, just like shown in the video.
Next, add the sugar and the wheat flour, mix all the ingredients together again until combined.
Close the jar again and let the mixture ferment for another 40 minutes.
After this indicated time, transfer all this mixture to a large bowl, pour in another 400g of wheat flour and knead very well by hand until a smooth and uniform dough is formed, then set aside.
Once you’ve done that, sprinkle 1 tablespoon of wheat flour all over an egg carton.
Place the dough we made over the carton, make a superficial slit in the center of the dough, sprinkle another tablespoon of wheat flour all over it. Cover the dough with a tablecloth and let it rest for 30 minutes.
After this indicated time, take to a preheated oven at 180°C (356°F) and bake for 30 minutes.
Serve.