Heat the stock in a large saucepan with the ginger, garlic, lemon juice, chilli, star anise, tamari and brown sugar, and bring to a gentle boil.
Add the chicken and shitake mushrooms and reduce the heat to simmer for 10 minutes. Add the carrots and Asian greens, and cook for a further 2 to 3 minutes.
Spoon the stock and vegetables into 4 bowls, add the sliced chicken, top with shallots and serve.