Chilled udon noodles with sesame vinaigrette

Method

1. To make the udon noodles, dissolve the salt completely 155ml/5fl oz water to make a brine.

2. Put the flour in a large bowl and make a well in the centre. Pour the brine into the well and gently flick the surrounding flour over the liquid, without pressing down.

3. Using your fingertips rather than your palms, quickly mix the flour and brine in a circular motion. Keep your fingers pointing down, like a rake, and continue mixing until the flour is no longer powdery and the mixture resembles small, even crumbs.

4. Once the moisture is evenly distributed, press the mixture firmly together with both hands to form a solid piece of dough.

5. Put the dough in a thick, food-safe plastic bag. Slowly step on the dough, using your body weight to flatten it. Remove the dough from the bag and fold it back into a ball.

6. Repeat the flattening and folding process, then return the dough to the bag and leave to rest at room temperature for 30 minutes.

7. Repeat the flattening and folding process again, then leave the dough to rest in the bag for 2 hours.

8. Step on the dough once more to flatten it. Keep it flat rather than shaping it into a ball, then return it to the bag and leave to rest for at least another 2 hours.

9. Using a rolling pin or pasta machine, roll the dough into sheets 2–3mm/⅛in thick.

10. Lightly dust the dough with tapioca starch and fold the sheet so it's easier to cut. Using a sharp knife, cut into 5mm/¼in-wide strips. Alternatively, use the tagliatelle cutter on a pasta machine.

11. Dust the cut noodles generously with tapioca starch, then shake off any excess.

12. Bring a large saucepan of water to the boil and add the cider vinegar.

13. Add the noodles and boil for 4 minutes. Drain, then immediately refresh in iced water to cool.

14. To make the goma ponzu vinaigrette, put the mirin, rice vinegar, 100ml/3½fl oz water, tahini, shiro miso, sesame oil, sugar, soy sauce and cayenne pepper in a blender. Blend until smooth.

15. For the tempura flakes, mix the cold water, tempura flour and aonori in a bowl using a whisk. The batter should be roughly mixed rather than completely smooth.

16. Heat the vegetable oil in a deep, heavy-based pan to 180C. Use a cooking thermometer to check the temperature.

17. Carefully drizzle the batter into the hot oil and fry until the bubbling stops.

18. Remove the tempura flakes from the oil and drain on kitchen paper.

19. CAUTION: Hot oil can be dangerous. Don't leave it unattended.

20. To serve, pour the goma ponzu vinaigrette into serving bowls.

21. Add the chilled udon noodles and top with the tempura flakes and spring onions.

22. Finish with a drizzle of chilli oil, if using, and serve.