Cut three freshly boiled potatoes into very fine dice, also one spring onion, two beetroots, and two tomatoes. Let all lay together. Season well. Mix one dessertspoonful of vinegar and one dessertspoonful of salad oil with about a tablespoonful of thick cream. Heap the vegetables in the centre of the bowl, and pour the sauce over them, and place round some clean, crisp lettuce hearts.