Peel and chop the potatoes and cook them in salted water for about 20 minutes until soft. Chop the beetroot finely. Boil eggs in boiling salted water for about 9 minutes
Melt the fat in a saucepan, then stir in the flour, sweat briefly, then add 250 ml of milk and stock while stirring. Add mustard and simmer for 5-8 minutes, stirring several times. Season sauce with salt, pepper and a little nutmeg
Drain the eggs, quench briefly under cold water and peel. Add eggs to the sauce. For the Gremolata, wash lemon hot, grate dry and thinly grate the peel. Peel garlic and chop finely. Wash parsley, shake dry and finely chop the leaves of 2 stems. Mix parsley, garlic and lemon peel
Heat 150 ml milk. Drain the potatoes. Add beetroot and milk to the potatoes and mash everything to puree. Season with salt, pepper and nutmeg. Arrange eggs and mashed potatoes on plates. Sprinkle with gremolata and garnish with remaining parsley leaves. Serve with salad