For the Dough:

• 1 7/8 cups (450 ml) lukewarm milk
• 1 teaspoon salt
• 1 tablespoon (20 g) sugar
• 2 teaspoons (7 g) dry yeast
• 1 egg white
• 2 tablespoons (30 ml) vegetable oil
• 5 1/3 cups (700 g) all-purpose flour

For the Filling:

• 1 pound (500 g) potatoes
• Salt to taste
• 6 ounces (170 g) grated hard cheese

For Brushing:

• 1 egg yolk
• 2 tablespoons milk

For Garnishing:

• Sesame seeds (quantity as desired)

1. Chop potatoes into small cubes, cover them with water in a pot, and boil until tender (about 15 minutes). Drain well.
2. In a large bowl, whisk together the lukewarm milk, salt, sugar, dry yeast, and egg white until mixed.
3. Stir in vegetable oil.
4. Gradually add flour, stirring with a spatula until the dough starts forming. Then knead by hand until smooth; the dough will be sticky at first—do not add more flour immediately.
5. Lightly oil your hands and shape the dough into a ball. Cover with plastic wrap and let rest in a warm place for 30 minutes, allowing it to rise.
6. Meanwhile, mash the cooked potatoes in a bowl. Season with salt. Add grated cheese and mix until uniform. Divide into 4 equal portions and shape into balls.
7. Once the dough has risen, transfer to a floured surface and divide into 4 equal balls. Flatten each ball.
8. Place a filling ball in the center of each flattened dough piece. Fold edges over the filling and seal well, shaping into a ball.
9. Arrange the stuffed dough balls on a baking tray lined with parchment paper, spaced apart. Cover with a clean towel and let rise 20 minutes.
10. Preheat the oven to 180°C (356°F), using upper and lower heat.
11. In a small bowl, beat the egg yolk with milk. Brush this mixture over the dough balls.
12. Make small finger indentations on the dough surface for decoration and sprinkle with sesame seeds.
13. Bake for 20 minutes or until golden brown.
14. Remove from the oven and allow them to cool slightly before serving.