Lao Bing (Teochew Flaky Lard Mooncakes)

Instructions

1. For the mung bean filling, soak the hulled split mung beans in cold water for 3 hours. Drain, spread in a heatproof dish and steam until they crush easily, 35 to 40 minutes. Mash or blend until smooth.
2. Cook the mashed beans with the granulated sugar, lard and salt in a nonstick pan over medium-low heat, stirring constantly, until the paste is stiff, no longer sticky and holds a ball shape, 15 to 20 minutes. Cool completely, about 1 hour, then divide into 8 balls of about 55 g.
3. For the water dough, mix the all-purpose flour, soft lard and granulated sugar, add the water and knead until smooth and elastic, about 5 minutes. For the oil dough, rub the all-purpose flour and soft lard together into a soft, smooth paste. Cover both and rest 30 minutes.
4. Divide the water dough into 8 pieces (about 35 g) and the oil dough into 8 pieces (about 21 g). Flatten a piece of water dough, set an oil dough ball in the center and wrap it, pinching to seal.
5. Roll each wrapped ball into a long oval, roll it up from the short end, turn it 90 degrees, roll out again into an oval and roll it up again. Cover and rest 15 minutes.
6. Heat the oven to 350°F (175°C) and line the baking sheet with parchment.
7. Press each coil flat, roll into a 4-inch (10 cm) round, set a filling ball in the center and gather the dough around it to seal. Place seam side down and press into a disc about 3 1/2 inches (9 cm) wide and 3/4 inch (2 cm) thick. Prick the tops twice with a toothpick.
8. Bake 15 minutes, flip each pastry with a spatula and bake until both sides are pale golden and the edges are flaky, 10 to 15 minutes more.
9. Cool on a rack at least 30 minutes; the filling is very hot and the crust firms as it cools.