Whisk the flour, yeast, sugar, and salt together in a large mixing bowl.

Combine the warm water, milk, and oil in a separate container and pour into the dry ingredients.

Stir until a shaggy dough forms, then move to a floured surface.

Knead the dough for several minutes until it becomes smooth and elastic.

Place the dough in a covered bowl and let it rest in a warm spot until it doubles in size.

Punch down the risen dough and knead briefly before dividing into twelve equal pieces.

Roll each piece into a circle and place a spoonful of thick custard on one half.

Fold the dough over the custard and press the edges firmly to create a secure seal.

Let the shaped buns rest under a towel for a short second proofing.

Heat a non-stick pan on the lowest setting and lightly brush with oil.

Place the buns in the pan and cover with a tight-fitting lid to trap the steam.

Cook until the bottom is golden, then flip and finish cooking without the lid until browned on both sides.