Whip well-chilled cream with chilled beaters in chilled bowl. Fold in remaining ingredients. Lightly oil a sheet of wax paper and roll horseradish mixture in the paper, making a cylinder about 1-1/2" in diameter. Freeze horseradish cream. To serve, unwrap and slice cylinder 1/4" thick. Use to garnish tomato, salmon, trout, ham, or veal. Keep frozen, removing slices as needed.
