As Sydney's winter chill settles in, few dishes offer the same kind of comfort as a bowl of steaming udon. Silky noodles slipping through a deeply savoury broth, infused with kombu and mushrooms, while tender greens and a softly set egg turn every spoonful into something nourishing and restorative.

For Chef Chris Kim, Head Chef of Ibushi at Sydney's Prefecture 48, it's the sort of meal that defines cold-weather cooking: simple ingredients transformed into deeply satisfying flavours. "This is the kind of dish I make at home when the temperature drops," Kim said ."Simple ingredients, deeply satisfying flavours, and a bowl that warms you from the inside out."

His tip? Swap the chicken egg for a duck egg. The richer yolk lends extra depth to the broth, creating a more luxurious finish that elevates this humble noodle soup into the ultimate cold-night supper.

Ingredients

Serves 4

For the Udon Noodles:

• 200g plain flour
• 12g sea salt flakes
• 90ml warm water

Shortcut: Good-quality udon noodles from your local Asian grocer work beautifully.

For the Mushroom Broth:

• 1.5L mushroom soaking liquid
• 10g kombu
• 25g dried mixed mushrooms, soaked overnight.
• 1 brown onion, roughly chopped
• 2 cloves garlic, chopped
• 1 small piece ginger, sliced
• 200g Swiss brown mushrooms, chopped
• 60ml light soy sauce
• 20ml mirin

For the Kombu Oil:

• 20g kombu
• 200ml vegetable oil

To finish:

• 300g mixed mushrooms (oyster, enoki and shitake mushroom work well)
• 2 handfuls baby spinach
• 4 onsen eggs or soft-boiled eggs
• Sea salt

Method

Make the Noodles

1. Dissolve the salt in warm water and gradually mix into the flour.
2. Knead for 5–8 minutes until a firm dough forms. Wrap and refrigerate for at least four hours.
3. Roll the dough thinly (about 2mm thick) and cut into noodles. Set aside until ready to cook.

Prepare the Mushroom Stock

1. Warm the mushroom soaking liquid and kombu to around 65°C and allow it to infuse for 10 minutes. Remove the kombu.
2. Add the soaked mushrooms, onion, garlic, ginger and Swiss brown mushrooms. Bring to a boil, then reduce to a gentle simmer for 30 minutes.
3. Strain and reserve the stock.

Make the Broth

1. Return 1 litre of the mushroom stock to a pot.
2. Add the soy sauce and mirin.
3. Bring to a gentle simmer and taste for seasoning.

Infuse the Kombu Oil

1. Roast the kombu at 150°C for 15 minutes until lightly golden.
2. Blend with the vegetable oil and leave to infuse while you prepare the remaining elements.

Prepare the Toppings

1. Heat a frying pan with a little oil. Cook the mushrooms until golden and caramelised.
2. Season lightly with salt.
3. Wilt the spinach in the same pan for 30 seconds.

Assemble

1. Cook the udon noodles in boiling water until tender.
2. Divide between four warm bowls. Ladle over the hot mushroom broth.
3. Top with the mushrooms, spinach and a soft egg. Finish with a drizzle of kombu oil.