Place the tomatoes into a roasting tray. Season generously with salt and black pepper then, drizzle over two tablespoons of the light olive oil and sprinkle over the oregano. Place in the oven. Cook for 2½ to 3 hours when the tomatoes should be half their original size. Remove from the roasting tray and allow to cool slightly.
If you can’t buy any ready cooked puy lentils, put the lentils into a saucepan with 1lt/1¾ pints of water and a really generous pinch of sea salt. Bring to the boil and then reduce to a simmer for about 20 minutes or until the lentils are tender. Drain well and run under a cold tap to cool slightly.
Place the lentils in a large bowl with the lemon juice and 5 tablespoons of the extra virgin olive oil and the roasted tomatoes.
Slash the mackerel several times. Season it generously with salt and pepper. Add the remaining light olive oil. Place the mackerel in a heavy-based frying pan, skin side down and cook for 3 to 4 minutes. Add the red, onion, capers chives and spring onions and Feta to the lentils, season to taste and mix well.
Turn over the fish and cook for one more minute.
To serve fold the rocket into the salad with the remaining olive oil check the seasoning and then divide between four plates. Place the mackerel on top and finish with a lemon wedge.
Notes & Tips
If you don’t want to spend the time roasting the tomatoes, you can just use raw ones.