Udon Noodle Soup

Method

1. 1

   Make the dashi

   Warm the water and kombu in a saucepan over low heat for 10 minutes, keeping it below a simmer; remove the kombu when small bubbles appear at the pan’s edge.

2. 2

   Steep the bonito

   Bring the kombu dashi just to a simmer over medium heat, turn off the heat, add the bonito flakes and steep for 5 minutes, until the flakes sink.

3. 3

   Strain the dashi

   Strain the dashi through a fine sieve into a heatproof bowl, without pressing or squeezing the bonito flakes.

4. 4

   Season the broth

   Return the dashi to the saucepan; add the soy sauce, mirin and sugar, then simmer over medium heat for 2 minutes, until the sugar dissolves.

5. 5

   Taste and adjust

   Taste the hot broth and add soy sauce in 1 tsp increments, up to 1 tbsp more, until assertively savoury but balanced; keep it at a gentle simmer for 1 minute.

6. 6

   Cook the mushrooms

   Add the shiitake and simmer over medium-low heat for 5 minutes, until the slices are tender.

7. 7

   Cook the udon

   Cook fresh or frozen udon according to the packet directions, cooking frozen noodles straight from frozen; boil until hot and springy, then drain well.

8. 8

   Wilt the spinach

   Add the spinach and grated ginger to the broth and cook over medium heat for 1 minute, until the spinach is wilted and bright green.

9. 9

   Serve

   Divide the udon among four bowls, ladle over the hot broth and mushrooms, top with spring onions and optional shichimi, and serve immediately.

Tips

• The broth should taste distinctly savoury before serving; adjust with soy sauce gradually, as noodle brands and dashi strength vary.
• Cook frozen udon straight from frozen and use the packet directions, since timings vary by product.
• For a fresh finish, garnish with grated ginger or shichimi togarashi, or add a little toasted sesame.

Swaps

• Use another sliced mushroom in place of shiitake.
• Use another tender leafy green in place of spinach.

Storing

Store broth and noodles separately in covered containers in the fridge for up to 2 days. Reheat broth until steaming and warm noodles separately, or add them to the hot broth just before serving.