Scald the tomatoes, quickly put into cold water and skin. Halve and seed, then slice the pulp.

Cut the green beans into 1-inch bars and boil in salted water. Chop the eggs and rinsed lettuce. Combine the prepared ingredients with the chopped greens.

To prepare the dressing heat the sour cream over water-bath, add the lemon juice, mustard, oil, salt and pepper. Continue heating the mixture over water-bath until it gets thick.

Before serving put the salad into a salad bowl, coat with the dressing and garnish with greens.