First heat 2 tablespoons of the oil in a heavy pan and soften the onion and garlic in it gently for about 10 minutes.
Then add the wine vinegar, the water, the crushed coriander and peppercorns, Herbes de Provence, the lemon juice and a little salt. Bring to the boil and simmer for 5 minutes.
Then prepare the courgettes: don’t peel them, just wipe them, trim off the ends and cut into 2.5cm slices. Add them to the sauce together with the chopped tomato, stir, put the lid on and simmer over a gentle heat for about 20 minutes, or until they’re tender.
Now transfer the lot to a serving dish, allow to cool, then cover and chill. Just before serving sprinkle with the remaining tablespoon of oil and the parsley. Then all it needs is some crusty fresh bread.