8 small plaice fillets, skinned, about 65 g (2 1/2 oz) each
salt and pepper
1/4 teaspoon ground ginger
1 small onion, finely chopped
150 ml (1/4 pint) white wine
150 ml (1/4 pint) chicken stock
2 green leeks, cleaned and cut into matchstick strips
4 tablespoons low-calorie mayonnaise
4 tablespoons natural low-fat yogurt
1 thin slice fresh root ginger
1/2 teaspoon mild curry powder
small croutons, to garnish