This easy, nutritious broth powered by shiitake mushrooms is guaranteed to cure winter woes. This soup starts with the steeping liquid from the mushrooms, so you don't even need to make stock. Substitute extra soy sauce for the fish sauce if you want to make it vegan.
6 dried shiitake mushrooms
1 tbsp fish sauce
1 tbsp soy sauce
1 tbsp sake (optional)
1 tbsp mirin
salt, to season
¼ Chinese cabbage
1 tbsp vegetable oil
1 tsp sesame oil
½ daikon (white radish), peeled and cut into large chunks
2 carrots, peeled and cut into large chunks
1 sweet potato, peeled and cut into large chunks
300g firm tofu, cut into 5cm cubes
3 thin spring onions, finely sliced
1. Rinse the shiitake mushrooms and transfer to a small saucepan. Cover with 1.5 litres of boiling water and stand for 20 minutes. Remove the mushrooms and trim and discard the stems. Halve the caps on an angle. Set mustrooms aside. Bring the mushroom steeping liquid to a simmer and add the fish sauce, soy sauce, sake and mirin. Taste and adjust the seasoning as required. The liquid should be strongly flavourful.
2. Trim the Chinese cabbage so the root is clean but the leaves are still connected to the root. Cut lengthwise into 4 thin pieces.
3. Place a large saucepan over high heat and add the vegetable oil and sesame oil. Add the daikon, carrot, sweet potato and mushrooms and stir-fry for about 2 minutes until just starting to toast on the outside. Pour the stock over the vegetables, add the Chinese cabbage and bring to a simmer. Simmer over low heat for about 15 minutes, skimming any scum that rises to the surface. Add the tofu and simmer for a further 10 minutes or so, until the vegetables are tender. Taste and adjust seasoning again, then serve scattered with spring onions.