In a large bowl, mix yeast, sugar, and warm milk. Stir until the yeast dissolves.

Gradually add flour and salt. Knead to form a soft, slightly sticky dough.

Sprinkle flour on a surface and knead the dough for 6-7 minutes until smooth.

Cover the dough and let it rest for 10 minutes.

Divide the dough into four equal parts, cover, and rest for another 20 minutes.

Sprinkle flour on a clean surface and roll out each dough portion thinly.

Spread softened butter evenly over the rolled-out dough.

Fold the dough (following visual or written instructions) and lightly brush with oil.

Repeat with the remaining pieces of dough, layering each piece over the previous one and buttering as you go.

Cover the dough and chill in the freezer for 25 minutes.

Thinly slice the potatoes.

In a bowl, mix the potato slices with cold cream, salt, and black pepper until evenly coated.

Preheat your oven to 190°C (375°F).

Roll out the chilled dough thinly and shape as needed. Place it on a lined baking tray.

Add the potato mixture to the center, spreading it evenly.

Sprinkle extra salt and black pepper over the filling.

Brush the edges of the dough with egg yolk for a golden crust.

Bake in the preheated oven for 30-35 minutes, or until golden brown.

Remove from the oven, sprinkle grated cheddar cheese on top, and add fresh rosemary if desired.

Return to the oven for another 8-10 minutes until the cheese melts and bubbles.

Slice while hot and serve. Enjoy the crispy, flaky layers paired with the creamy potato and cheese filling!