Remove the outer leaves from the pointed cabbage, halve the rest and cut into bite-sized strips. Wash the pointed cabbage strips. Clean and wash the carrots and cut into thin slices. Cook both in a little salted water for about 10 minutes, until the vegetables are soft but still crisp. Drain the vegetables, collect the cooking water and measure out 100 ml.
Put the cornstarch with about 100 ml of cold water in a well-sealable container, e.g., a clean jam jar, close the lid and shake everything until the cornstarch has dissolved in the water.
Heat the margarine in a saucepan, pour in the horseradish, the leftover cooking water and cream. Stir in the mixed cornstarch, bring to the boil briefly and then simmer gently for 3-4 minutes until a creamy sauce is formed.
Mix the vegetables with the horseradish cream and sprinkle with the chives.