Warm the olive oil in a pan and add the chopped shallots or onions, the garlic and the herbs. It’s best to have the herbs in sprigs, as these can then be easily removed at the end of cooking. Allow the shallots and herbs to cook for 4–5 minutes until tender.
Cut the tomato flesh into 5 mm (¼ in) dice and add to the shallots. Have the pan on a very low heat, just on a light simmer, and c