Combine one dessertspoon of lemon juice, 1/2 teaspoon oregano, a couple of twists of salt and pepper in a medium bowl. Gradually add 3 dessert spoons of olive oil then mix well with a whisk.

Wash the tomatoes and quarter them, removing the bit where they were attached to the vine. Remove the leaves of the parsley and chop reasonably finely. Add parsley and tomatoes to the salad bowl then add the dressing; toss to coat.