Wash the meat, dab dry. If necessary, cut a thin layer of fat. Rub meat with salt and pepper. Fry in a roasting pan in hot clarified butter all around for about 5 minutes. Bake in a hot oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3) for 30-40 minutes.
Hard boil eggs. Quench, peel and let them cool down. Mix salad cream, sour cream and cucumber water. Dice cucumbers. Wash parsley and chives and chop finely, except for a little bit. Chop the eggs.
Stir it all in. Season to taste with salt and pepper.
Remove the roast beef and let it cool down. Cut thinly and serve with tartar sauce. Garnish with the rest of the herbs.