Fry the shallot and bacon in a saucepan in 10 g butter. When they have turned color, add the potato, beet and carrot cubes. Sweat while stirring vigorously, sprinkle with marjoram, pepper and salt and deglaze with the stock. Bring everything to a boil and then simmer for about 8-10 minutes over medium heat. Since the stock (intentionally) does not cover the vegetables, stir them every now and then while they are cooking. After 8 minutes have elapsed, take a sample of the 3 types of vegetables. They should still be very slightly firm to the bite. If so, remove from heat, pour through a sieve and let cool. Catch the brew and later use it for the sauce.