Soak the mung beans in cold water for 2 hours. Once the beans have expanded, rinse them well and steam until cooked.

To make the filling: Finely chop the mung bean balls and place them in a pan. Add a little water to dissolve the beans. Cook over medium heat, stirring until the mixture thickens. Add sugar, candied winter melon, pumpkin seeds, and shredded coconut. Stir until the filling is dry. Make the filling slightly sweeter than usual.

Let the filling cool, then shape into small balls.

Divide the dough into small portions. Take a piece of dough, roll it into a ball, then flatten it. Place a filling ball in the center, wrap the dough around it to seal, and roll into a smooth ball. Gently flatten the ball and make a small indentation in the center to resemble traditional bánh chay.

Bring 4 1/4 cups water (1 liter) to a boil in a pot. Drop the dumplings in and cook until they float to the surface. Let them cook for another 1-2 minutes, then remove and place in a bowl of cold water for 5 minutes to cool. Serve 3 dumplings per bowl.

After removing the dumplings, add sugar to the cooking water and stir until dissolved (adjust sweetness to taste). Dissolve tapioca starch or cornstarch in cold water, then slowly add to the pot, stirring until the liquid thickens. Bring to a boil, add a few drops of pomelo blossom extract, then turn off the heat.