Chicken, lime and lemongrass soup

Name: Chicken, lime and lemongrass soup
Prep time: 30 min
Cook time: 1 h
Total time: 1 h 30 min
Cuisine: Asian, Thai
Ingredients: 2 litres/3½ pints fresh chicken stock; 2 lemongrass stalks, bruised plus 1 tbsp finely chopped; 4 slices galangal, each about the thickness of a £1 coin; 9 Thai shallots, 3 peeled and left whole, 6 thinly sliced; 2 chicken breasts; 6 tbsp lime juice; 3–4 tbsp fish sauce; pinch finely chopped bird's-eye chillies; 1 tbsp lemongrass, finely chopped; 1 handful fresh coriander, roughly chopped, to garnish