Crumble the stock cube into a measuring jug. Add 750ml boiling water. Stir till the stock cube has dissolved.
Peel the ginger. Cut it into thin matchsticks. Put the ginger, star anise and 1 tbsp of the tamari in a pan. Add the stock. Cover. Bring to a simmer.
Using a spiraliser or vegetable peeler, slice the aubergine into long, thin ribbons.
When the stock is simmering, add the chicken. Simmer for 5–6 mins till the chicken is cooked through. Add the aubergine ‘noodles’ and a bundle of the Thai rice noodles. Simmer for 3 more mins.
Wash the bean sprouts in a colander and drain. Trim the spring onions. Finely slice them on the diagonal. Slice the chilli into rounds. Pick the leaves off the mint sprigs. Slice the lime into wedges.
When the chicken is cooked, divide the aubergine and chicken between two bowls (tongs are handy here, or a slotted spoon). Ladle the broth over the top.
Pile some bean sprouts, spring onion, chilli and mint on top of each soup. Serve with the lime for squeezing.