Mackerel, Tomato Water and Raspberries

• 2 kg (4 lb 8 oz) mixed variety of organic tomatoes, very ripe, halved
• 20

Put the tomatoes in a large, deep-sided frying pan over low heat. Simmer slowly for about 15 minutes. Strain through a fine sieve to achieve a clear consommé. Add the thyme while still hot and set aside for at least 30 minutes for the flavours to infuse. Strain again through a fine sieve and set aside to cool.

Just before serving, cut the mackerel into