Ingredients

• 250g very thinly sliced beef rump (make sure it is sliced across the grain)
• 8 whole dried shiitake mushrooms
• 6 cups beef stock
• 1/4 cup light soy sauce
• 4 spring onions, coarsely chopped, plus extra, thinly sliced, to serve
• 5cm piece ginger, peeled and coarsely chopped, plus extra, finely grated, to serve
• 1 head of garlic, halved
• 4 small bok choy, cut into 3cm pieces
• 2 tablespoon mirin (see notes)
• 300g dried udon noodles
• Sesame seeds, to serve
• Sesame oil, to seve

Method

• Step 1 Place dried mushrooms in a bowl, pour over boiling water to cover and set aside to soften while you make the soup base. Bring stock, soy sauce, spring onion, ginger and garlic to the simmer in a large saucepan over medium heat and cook for about 10 minutes to develop the flavours. Strain (discard solids) and return soup to pan. Drain mushrooms, slice off the tough stems and discard, then thickly slice the mushroom cap and add to soup (you can add a splash of the soaking water too if you like for extra flavour). Bring back to the simmer, add bok choy and simmer for about 2 minutes until just tender, stir in mirin and season to taste.
• Step 2 Meanwhile, cook noodles according to packet directions, drain and divide among bowls, then pile beef on top. Ladle over soup and serve hot, scattered with sliced spring onion and sesame seeds, a drizzle of sesame oil and with extra ginger and soy sauce to add to taste.