- 250g very thinly sliced beef rump (make sure it is sliced across the grain)
- 8 whole dried shitake mushrooms
- 6 cups beef stock
- ¼ 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 tbsp mirin (for alternative, see note)
- 300g dried udon noodles
- Sesame seeds and a drizzle of sesame oil, to serve
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.
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.
Mirin is a lightly sweet rice wine condiment available in the Asian section of many supermarkets or at specialist Asian supermarkets. If you can’t get it, stir 3 tsp sherry with 1 tsp caster sugar and for every tablespoon required. If you prefer a non-alcoholic alternative, use water instead of sherry.
- The heat from the broth is enough to cook the beef, so ladle the broth directly over the meat to get this happening.
- To help slice the beef as thinly as possible, place it in the freezer for about 20 minutes to firm up, then slice with a very sharp knife – always slicing across the grain.