I think that mackerel is such a beautiful looking fish, with its distinctive black and blue colourings and its mini, tuna-like body. I like cooking them whole like this in my wood-fired oven in Dorset – they just curve gently round the edge of a cast-iron frying pan as they cook in a couple of minutes in the intense heat.
4 mackerel, weighing about 200-250g each, gutted
A little vegetable or corn oil for brushing
2 medium shallots or a small red onion, peeled, halved and thinly sliced
A small handful of mint leaves
The juice of half a lemon
Salt and freshly ground black pepper
Preheat the oven to 200C/gas mark 6.
Cut the cucumber into 4-5cm lengths, then stand them on their ends and cut thin slices down on each side, avoiding the seeds and discarding them. Cut the slices into thin strips and mix them in a bowl with the shallots, mint leaves and lemon and season to taste.
Brush the mackerel with a little oil and season. Curve them around a round, oiled oven dish or frying pan and bake for 6-8 minutes, or until they are just cooked.
Serve with the salad.