• 6 cups (1.5 litres) vegetable stock
• 2 lemon grass stalks, tender white parts only, thinly sliced
• 4 kaffir lime leaves
• 1 red chilli, deseeded and very finely chopped
• 2 shallots, finely chopped
• 6 garlic cloves, finely chopped
• 5 cm galangal or ginger, cut into 1 cm slices
• 2 cups (180 g) mixed mushrooms, such as button, oyster and shimeji
• 1 cup (150 g) cherry tomatoes, halved
• ½ teaspoon chilli flakes
• 2 teaspoons concentrated tomato purée (paste)
• 2 teaspoons coconut sugar (or grated palm sugar)
• 1 tablespoon light soy sauce
• 2 tablespoons lime juice
• 1 block (300 g) extra-firm tofu, pressed and cubed
• ¼ teaspoon salt
• coriander (cilantro) leaves, to garnish

Put all the ingredients except the coriander into a large saucepan. Bring to the boil, then reduce the heat to low, cover and simmer for 20–30 minutes until all the flavours have infused and your kitchen smells of lemongrass and ginger.

Serve the soup piping hot, garnished with coriander.