Serves 4

Sousing is an old-fashioned way of preserving your catch, and the end results are quite delicious. Tomato growers might find that it's a good idea to preserve your crop in a similar way. If you have both mackerel and tomatoes in ready supply at this time of the year you may just want to try this dish out. I've tweaked the conventional recipe here which I learnt from my grandmother. She used to make it when I turned up at home with carrier bags full of mackerel that I had caught with my mates.

8 mackerel fillets, trimmed and boned
2 small onions, peeled and finely chopped
1 bay leaf
1tsp coarsely ground black pepper
1/2tsp fennel seeds, crushed
2tbsp extra virgin rapeseed oil
75ml malt vinegar
75ml water
6 tomatoes, skinned, seeded and roughly chopped
200g samphire, trimmed of woody stalks

Pre-heat the oven to 180C/gas mark 4. Roll up the mackerel fillets skin-side out and secure with cocktail sticks. Put them in an ovenproof dish, not too close together. Gently cook the onions, bay leaf, black pepper and fennel in the rapeseed oil for 3-4 minutes until soft, stirring occasionally. Add the vinegar and water, bring to the boil and simmer for 2 minutes. Stir in the tomatoes and season with salt, then pour over the mackerel. Cover and cook in the oven for 30-40 minutes; remove and leave to cool.

Meanwhile, blanch the samphire in unsalted boiling water for 30-40 seconds, then drain and refresh under cold water. The mackerel can be stored in the fridge for up to a week or served on the day scattered with the samphire.