Cut off the root end, then cut 4 gashes through the red peel from the root end almost to the stem (do not cut all the way through). The thinner the slices the better. Loosen the 4 sections gently so they start to stand out from the radish. Chill in ice cubes until the "petal's start to slightly curl back. For more detail, make thin circular slices of the red skin from the outside of a second radish and insert these slices between the petals.