350 g (12 oz) boneless chicken breasts, skinned
1 tablespoon dry sherry
4 spring onions, chopped
1 x 2.5 cm (1 inch) piece fresh root ginger, finely chopped
2 tablespoons oil
1-2 garlic cloves, thinly sliced
2 celery sticks, sliced diagonally
1 small green pepper, seeded and sliced
2 tablespoons light soy sauce
juice of 1/2 lemon shredded
rind of 2 lemons
1/4 teaspoon chilli powder