Combine 1.25 litres stock, one or two red chillies (optional), two garlic cloves, and a thumb of fresh ginger, all finely sliced, with the grated zest of one small lemon and one small lime, and two tablespoons Thai fish sauce. Simmer for five minutes.
Add a large carrot cut into matchsticks, 350g chicken in 5cm x 0.5cm strips, and 250ml coconut milk. Simmer for five minutes, then add 70g finely shredded kale or cabbage, and any leftovers of cooked meat. Simmer until just tender then add 60ml lemon juice or lime juice or both and handful of coriander leaves.
You can also add noodles – you might need to pre-cook them at the start.