Wash, clean and peel the carrots and horseradish. Cut into small cubes. Peel onions and cut or slice into thin rings. Crush pepper and spice grains partly in a mortar. Boil up all spices, prepared vegetables, sugar, 5 tablespoons of water and vinegar in a pot. Let the brew cool down lukewarm.
Put the matie in cold water for about 20 minutes. Drain the matjes, dab dry and cut into pieces about 2 cm wide. Put them into a closable container. Pour the stock over it and leave everything closed in the refrigerator for about 3 days.
Wash potatoes thoroughly and cook in boiling water for about 20 minutes. Mix sour cream and sour cream, season to taste with salt and pepper. Wash chives, dab dry and cut into fine rings. Drain potatoes and let them evaporate. Serve the maties with potatoes and cream sauce. Sprinkle with chives.