Filling: Soak the mung beans for 4 hours until soft. Add just enough water to cover and cook until tender. Puree the beans, then add 3 tablespoons sugar and a pinch of salt. Cook over medium heat, stirring until the mixture dries out. Gradually add 35 grams (2 1/2 tablespoons) vegetable oil while stirring. Mix in the cornstarch and glutinous rice flour, then add 2 tablespoons durian and mix well.

Continue stirring the mung bean mixture until it is dry and smooth. When it no longer sticks to the pan, transfer to a bowl and cover with plastic wrap to prevent drying out.

Cook the durian with 3 tablespoons sugar over medium heat until the sugar dissolves. Soak the salted egg yolks briefly in a little wine, then rinse. Steam the yolks with a little oil until cooked.

Outer dough: Mix all-purpose flour, sugar, and vegetable oil. Gradually add water and knead until the dough is smooth and soft. Cover and let rest for 30 minutes. Inner dough: Mix all-purpose flour and lard (or substitute vegetable oil, but lard gives better flavor). Knead until smooth, then let rest for 30 minutes.

Divide the mung bean filling into 12 portions and roll into balls. Flatten each ball, add a small spoonful of durian in the center, then place a salted egg yolk on top. Gather the edges and seal. Lightly oil your hands to prevent sticking.

Repeat to make 12 filled balls. Divide both the outer and inner dough into 12 equal portions.

To assemble: Roll each outer dough piece into a thin rectangle. Place an inner dough piece on top and press to adhere. Roll up, then fold into thirds and roll out into a circle.

Place a filling ball in the center of the dough circle and gather the edges to seal. Use a stamp dipped lightly in red food coloring to gently press onto the top of each pastry, flattening slightly.

To bake: Place pastries seam side down on a baking sheet. Preheat oven to 400°F (200°C). Bake for 15 minutes, then remove and brush the tops with a mixture of egg yolk and a little vegetable oil.

Bake a second time for about 10 minutes at 350°F (180°C). Let the pastries cool before transferring to a plate, as the crust is delicate. Pía pastry is also called 'peeling pastry' because the crust separates into layers when eaten. Follow these detailed steps for best results.