Wash the mung beans and soak them in water one night in advance, and the next day you can see that the mung beans are cracked because they have absorbed enough water. The first thing you need to do is to rub off the coat with the same strength as you would if you were washing rice, and then rinse the coat with running water to separate it from the rest of the water. Add water and cook, stirring into a paste with a food processor.
Ingredients (2), fried bean paste.
Heat a non-stick pan, pour in the mung bean paste and add sugar, stir fry until the bean paste is dry, add oil, continue to stir fry into a ball shape can be closed. Hand pinch up small pieces, if you can roll into a small ball and not scattered, that is, the mung bean filling has been, loaded up and cooled to be used.
Ingredients (3), oil skin.
Sift the flour, melt the sugar in warm water, then put all the ingredients of (3) into a large bowl, mix with a spatula until there is no dry powder, then pour it on a silicone mat (without a mat, you can work on a smooth surface), push and knead the dough into a long strip, fold it in half, then push and knead it into a long strip, fold it in half, until the dough becomes tendon and can be supported by a film. Knead until smooth, then cover the dough with a bowl to prevent it from drying out and loosening.
Material (4), oil crust.
Sift the flour, pour it onto a work surface, make a hole in the center of the flour pile, put in the lard, rub the mixture with a spatula until it forms a ball, cover the dough with a bowl to prevent it from drying out, and then loosen it.
Split and loosen.
While the crust is loosening, roll the cooled mung bean filling into 10 20g balls. Then, cut and roll the dough into 10 equal-sized balls (14g/pc) and 10 equal-sized balls (10g/pc). This process gives the crust time to relax twice. Cover all the balls with plastic wrap to prevent them from drying out, and remove them as you go.
Make the puff pastry: one roll.
Roll the pastry into an olive shape, place it on a work surface and roll it out with a rolling pin into a long oval sheet about 2mm thick. Roll the pastry into an olive shape and place it in the center of the pastry sheet, continue to press it with the rolling pin into a size smaller than the pastry, taking care that the edges do not stain the pastry. Roll up from one end of the long side, cover with plastic wrap and loosen.
Making the puff pastry: two rolls. Roll out the pastry from the previous step with a rolling pin into a long oval sheet about 2mm thick (the longer the better, but don't break the skin with brute force), then roll it up from one end of the long side to form a tube, cover with plastic wrap, and loosen.
Make the puff pastry: press the shape. Take a piece of puff pastry, cut it off at one-third of its length with a knife, place both halves cut side down, flatten it, press the smaller piece on top of the larger one, and roll it out with a pasta stick to form a disk slightly thicker in the center and thinner at the edges, about 10 cm in diameter.
Pack the filling and shape.
Place a mung bean ball in the center of the puff pastry (keeping the knife cut side out), tighten the opening like a bun, close the opening down and shape. When you reach the last two, preheat the oven to 180 degrees.
Bake and cool.
Arrange the buns on a greased baking sheet and place in the preheated oven. Bake at 180 degrees Celsius for 15 minutes, 150 degrees Celsius for 5 minutes, turning off the heat when the top of the pastry is slightly charred. Remove from the oven, let cool completely and store in a moisture-proof box.