Cook chicken breasts in salted water for 45 minutes. Remove and leave to cool. Wash and separate lettuce.
Make the vinegarette: Mix mayonnaise, cream, horse radish, ketchup, orange juice and brandy together in a small bowl. Season to taste with salt and pepper.
Peel eggs and cut into quarters. Cut tomatoes into quarters or eight parts and remove seeds. Cut chicken breasts diagonal into slices. Marinade lettuce leaves with 1 tbsp. marinade. Cover 4 plates with lettuce leaves. Arrange in the middle of the plates sliced chicken breasts and pour over the rest of marinade. Garnish with eggs and tomatoes.