6 to 8 hours. For a really clean cut and stable frosting, head overnight pretty much.
Trenching too early can crack the frosting and make the trenches less regular.
What knife to use to get clean slices?
Use a well-sharpened knife, ideally a long, thin blade. Before each tranche, you can wipe the blade to prevent frost formation. Trim in slow motions, without sawing too hard, to preserve the dew and shine.
Conclusion
Your cold parsley ham becomes truly spectacular thanks to broth cooking, straining, light reduction of the juice
