In a bowl, combine bread flour, melted butter, milk, and salt.

Mix until well combined, then knead into a smooth dough.

Wrap the dough with cling wrap and let it rest in the fridge for 1 hour.

Place 1 potato into a pot of boiling water and cook for 20-25 minutes, or until fully cooked.

Once cooked, remove the skin from the potato and mash it with a fork.

Season the mashed potato with ground black pepper, salt, garlic powder, and milk. Mix well.

Take the rested dough out of the fridge and roll it out into a 22cm circle.

Place a layer of shredded mozzarella cheese in the center of the dough.

Spread the mashed potato on top of the cheese, followed by another layer of mozzarella cheese.

Fold the edges of the dough over the filling and seal the opening tightly.

Turn the dough over and gently roll it out again.

Brush a frying pan with butter. Place the bread dough in the pan and brush the top with more butter. Cook on low heat until golden brown.

Flip to the other side and cook until golden brown. Serve immediately.