Mix flour, water and salt until smooth. Through a sieve, pour the mixture into a bowl then cover with cling film. Keep refrigerated for at least 8 hours or overnight.
Remove the bowl from the fridge. You will see a layer of clear water on top. Carefully spoon out the water, then stir the batter very well.
Steam the noodles
Brush a thin layer of oil onto a small, light baking tray / sheet pan (see note 1). Pour in some batter to thinly cover the tray.
Bring water to a boil in a wok (or a deep frying pan) over a high heat. Gently place the tray on the water to float. Cover with a lid. Cook for around 2 minutes until you see bubbles appear and the noodle is not sticky when touched by hand.
Remove the tray and float it on cold water (e.g. in a sink) to cool. Peel the noodle off the tray then transfer to a chopping board. Brush a thin layer of oil on its surface. Repeat the procedure to finish the rest of the batter. Lay noodles one on top of another (see note 2).
Make the dressing
Put Chinese cinnamon, star-anise, bay leaf, fennel seeds, Sichuan peppercorn and water in a sauce pan. Simmer for 5 minutes then add corn starch and water mixture. Remove from the heat when it becomes a bit thick. When completely cool, discard all the spices then add black rice vinegar and minced garlic.
Assemble the noodles
Slice the noodles into strips of desired width then put into serving bowls. Garnish with cucumber, coriander, fresh chilli (if using) and sesame seeds. Pour the cooked sauce, Chinese chilli oil and sesame oil on top.
Notes
1. How to choose the tray: In China, people use round trays made of stainless steel or aluminium which are not usually available in regular supermarkets in the West. Luckily, you can simply replace them with baking trays (sheet pans). Whatever you choose, remember the following:
They should be small enough to fit into your wok (or deep frying pan);
They should be light enough to float on the water;
They should not have a loose base (e. g. if you use a quiche tray).
It’s better to use a non-stick tray. You only need to brush oil once. If your tray does not have a non-stick coating, you will need to brush it with oil each time before you pour in the batter.
2. Efficient rotating method: To save cooking time, I always use two trays to rotate. While waiting for the noodle on the first tray to cook, you can oil and fill the second one with batter.Right after you remove the first tray from the steamer, you can place the second one in. By the time you peel the cooled noodle off the first tray and fill it again with batter, the second one will be ready to take out.