Preheat the oven to 80 °C and heat a plate with it.
Season the beef fillet medallions with salt and pepper. In the very hot clarified butter on both sides in each case after thickness meanwhile altogether 2-2 1/2 min heartily sear. Immediately transfer to the preheated plate and cook in the 80 °C oven for approx. 45 min.
For the sauce, slowly melt the butter over a low heat. Cool down to hand heat.
Boil sherry and soup by half. Pour into a metal bowl. Fold in the egg yolks. Whisk everything heartily over a water bath that is only just lightly boiling, until the mixture is about 60 degrees and very creamy. Now gradually add the liquid butter in a thin stream. Then add horseradish and sour half cream. Continue to beat the sauce until it thickens to a creamy consistency. Season with salt, pepper and horseradish if desired.
Arrange the beef medallions on hot plates and cover one half of each piece of meat with a little hollandaise sauce. Serve the rest of the sauce separately.
Serve with hash browns or French fries.
For the small household Two people: halve the ingredients.
One person: The sauce cannot be prepared in a smaller mass than for 2 people.
Tip & Trick:
Horseradish The pungent root has nothing to do with the ‘sea’, but it does with the related radish. Horseradish derives from the word Maehre, the old word for horse, because the plant was once used in front of all