1Make the sauce: mince half a white onion, two garlic cloves, and thinly slice one stalk of spring onion. Mix with 5g of chilli flakes, 30ml of light soy sauce, 15ml of black vinegar, 30ml of Lao Gan Ma, 5g of granulated sugar and 1g of salt. Pour in 60ml of smoking hot oil to cook and mix.
2Boil and mash two potatoes (500g) with 1/2 tsp of salt until they flake apart.
3Mash the potatoes while they are still hot, then immediately add 260g of potato starch and 160ml of water to form a dough.
4Roll the dough into long, thick noodles.
5Boil the noodles for about two minutes until they float.
6Put the noodles in a pan with the sauce and toss to coat.