Combine the flour and salt in a large bowl. Pour in the hot water a little at a time, stirring with a spatula or chopsticks. When the dough starts to turn lumpy, knead it for 5 minutes. It should be smooth and not stick to your hands or the sides of the bowl. Add a little more flour if needed. Grease the bowl with 1 tablespoon of vegetable oil and roll the ball of dough around it to coat. Cover with cling film and let rest for 40 minutes.
Divide the dough into 3 equal portions. Dust your work surface with flour and roll one piece of dough into a 35x25cm rectangle, as thin as possible.
Brush the dough with chilli oil, sprinkle with spring onions and dust with a little flour. From the long side, roll it into a tight log, pressing out all the air. Roll the log into a circle (shape of a snail). Tuck the end underneath so it doesn’t unravel when cooking. Cover with clingfilm and let it rest while you repeat this process with the other two pieces of dough.
Heat 1 tablespoon of oil in a frying pan. Gently roll out each coiled dough into a circle that is 3-5mm thick. Dust with flour and cook for 3 minutes on each side. The pancakes should be golden brown and crisp. Enjoy them hot with more chilli oil.