Peel the carrots, apples and onions. Quarter and core the apples. Cut everything into small cubes and cook covered in the broth for about 20 minutes over medium heat. Shortly before the end of the cooking time, let the liquid boil down completely in the open saucepan. Let cool down.
Finely puree the vegetables, stir in the mayonnaise, 4 tablespoons chives and the horseradish, season with salt and pepper. Spread the cream thickly on the bread and serve sprinkled with chives.
The cream is also ideal for buffets as a fine dip for raw vegetables and crackers or as a spread on pumpernickel.