Into a bowl, add the water and the sugar, mix well.
Add the milk, the dry yeast powder and the 2 tablespoons of wheat flour, mix again until combined.
Once you’ve done that, cover the bowl and let this mixture rest for 10 minutes.
After this indicated time, add the oil, the egg white and mix well again.
Now add the wheat flour gradually and the salt, keep mixing well and adding the flour. When you can no longer mix with the spoon, knead by hand until it reaches the right consistency.
After that, put the dough in a bowl, cover with plastic wrap and let it rest for 40 minutes.
Meanwhile, into a skillet over low heat, add enough oil to cover its bottom and add the onion chopped into dices, stir until it starts to brown slightly.
Add the sweet paprika, the chili flakes and the salt, stir until brown, remove from the heat and set aside.
Into a bowl, add the boiled potatoes and mash them well into a mash, add the onion we’ve fried, mix well and set aside.
Once the dough has risen, sprinkle some flour on a table and place the dough on it, then round the dough and split it into 2 equal-sized pieces.
Flatten one of the pieces by hand making sure it’s not too thin nor too thick.
Now add half of the potato filling and close the dough by folding it over the filling, then make a hole in the center of the stuffed bread.
Repeat this process with the other half of the dough.
Transfer the dough to a baking sheet lined with nonstick paper and brush 1 egg yolk mixed with 1 teaspoon of milk all over the bread.
Finally, with a fork, draw lines all over the bread.
Bake in a preheated oven at 180°C (356°F) for about 30 minutes. Baking time may vary depending on the power of your oven.
Serve.