Dissolve the yeast and sugar in the warm water, leave it to bubble.
Sift the flour, make a well in it, put 2 of the eggs, the oil, salt and effervescent yeast. Start kneading while gradually adding the warm milk. Knead to obtain a soft, nonstick dough.
Divide the dough into 4 parts. Roll out 2 of them into thin sheets and wrap them into rolls, cut them lengthwise, then twist them about each other in pairs. From the 3rd part of dough, make a ball, on top of which you'll be putting the grid.
From the 4th part, roll out a sheet, cut it into strips and make the grid (see photos to get a better idea). Leave it to rise for 40 min., smear with the 3rd egg, sprinkle with seeds of your choice. Bake at 392°F (200 °C) until ready.