Since no-one has responded to this, I (a complete noob, mind you!) will make a suggestion based on my exceptionally limited experience (had ours for 10 days), my look at what the other recipes do, and blind faith that if I steer you wrong, someone will jump all over me on it, in which case, I will have taken a virtual bullet for your Christmas ham (a completely reasonable bargain from my point of view).
All disclaimers apply about not relying on advice, not fit for any particular purpose, can’t sue me if your ham is ruined or someone gets sick, blah, blah, blah…
I would do a cook using the temperature probe rather than time. Here in Ottawa, a spiral ham is actually a proper leg, bone-in, that comes improperly cooked and must be heated to temperature to be safe. If it were me (and it would have been, except my son – part of my bubble, so it’s okay, okay? – is bringing the ham), I would
- Set the probe temperature to 145, steam to 50% and cook it for as long as it takes for the probe to reach temperature. I’m guessing 3-4 hours, but it could be longer. But you can hold food at a given temperature, so I’d start it at least four hours ahead, and…
- If it reached 145 too early, I’d then hold it using the oven temp (not the probe temp) at 142, 50% steam until 45 minutes or so before dinner. You’re no longer cooking, you’re just holding, so you should be fine. At that point…
- Stop the oven, open the door to de-steam the oven, and do a (new) regular back-burner bake for 15-20 minutes at 375 (0% steam) to brown the ham.
- Glaze the ham and continue to bake for another 10 minutes or so
- Pull it out and let it rest
Again, I am a complete noob, and this is just a series of educated guesses. I’ve chosen 145 (probe) degrees because, normally, the temperature at the bone is supposed to be a MINIMUM of 140, but a spiral ham is, by definition, vented to the bone, so a few extra degrees won’t kill you (but a few less might ). The browning and glaze-setting times are a guess at best, but, at that point, you’re doing a regular bake, so, for the glaze, at least, the instructions on your ham for setting the glaze should be entirely accurate. It’s the browning I’m not sure about, but maybe your ham (or your experience) offers advice on that as well.
One last thing: We always end up with a crap-ton of leftover ham, and it freezes just fine after it’s cooked. I wouldn’t mess with carving it up pre-cook, because that just complicates things. Good Tupperware (wait – is that even a thing outside of Canada? Are YOU outside of Canada?), freezer bags, or a vacuum sealer will take care of freezing cooked leftover ham just fine.
Okay, I’ve set myself as the target. Let’s see if anyone flames me and saves your ham, or if anyone thinks I’m close.
I wonder if @chatnoir or @BestGFBaker (who have been kind enough to respond to my own queries in the past) might be able to chime in…
Good luck – have a safe and happy holiday season!