Wash the beetroot and boil in boiling water in a large pot for about 30 minutes. Wash the potatoes and add to the beetroot after about 10 minutes. For the marinade, whisk vinegar, broth, salt, pepper, mustard and honey. Add oil drop by drop. Peel shallots and cut into rings. Roast cumin in a pan without fat. Mash finely in a mortar.
Drain beetroot and potatoes and rinse under cold water, drain and remove the skin from the potatoes. Peel, halve and slice the beetroot. Cut the potatoes into slices. Mix the potatoes, beetroot, shallots and marinade and leave to marinate in the refrigerator for at least 1 hour. Mix cream and horseradish, season to taste with salt, pepper and lemon juice. Arrange salad, roast beef and dip
Waiting time approx. 1 hour