Melt chocolate - Double boiler.
Pour it onto the table top, best if it is a marble top.
Work quickly, use a frosting bended palette knife to spread thinly on the surface.
Let it set (it wouldn't take long), but make sure it doesn't set firmly. (If you're unsure, whether it is ready, test a small area first)
Use a knife, angled at 40 degrees and comb towards you. Apply even pressure, the chocolate curls will form naturally. (if it keeps breaking and doesn't curl naturally; you've waited a little too long for it to set or your chocolate isn't spread thinly enough for it to curl naturally.)
Keep in the fridge until it is ready to use.