Stuffing
Into a bowl, add the water and the dry yeast powder, mix very well, add the egg and the oil and mix very well again.
Add the wheat flour and the salt, mix until combined, add another 2 cups of flour, mix again until combined.
Add another 2 cups of flour (totaling 6 cups), and mix with your hands when the dough gets too consistent.
Knead the dough for 5 minutes and let it rest for 10 minutes.
Then sprinkle flour on the table and place the dough on it, roll out this dough with a rolling pin and make it a bit thick.
Add the stuffing.
First, add the ham, then the mozzarella, the tomato slices and sprinkle some oregano to taste.
Carefully roll the dough over the stuffing, and once it's rolled, tuck down the ends of the dough. Transfer this bread to a baking tin greased with flour and butter, let it rest for 30 minutes.
Brush a yolk mixed with a drizzle of olive oil or oil all over the dough.
Bake in a preheated oven at 200°C (392°F) for 40 to 50 minutes or until golden.
Serve.