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Hi Ellen: We're doing a dinner for a homeless shelter for St. Nicholas Day, including (already cooked boneless smoked ham) and a potato gratin. Potatoes are thin-sliced and started in halfnhalf stove top and then finished in oven with cheese on top. I'll do them in hotel pans. We're planning for around 150, thinking 50lb of ham (these guys are hungry) have a Garland stove with double oven and Nesco 18qut. roasters and standard hotel-pan holding chafers. Oven space is the issue--I can't do the hams/gratin at the same time. Don't want the hams to dry out but my inclination would be to bring it to safe temp in the oven first and slice it, moisten it a little and hold it in the roasters while the potatoes cook in the oven. So I'd probably be holding the ham 60-90minutes before service. Does this makes sense--any other suggestions?
How about doing the potatoes straight into the roasters from the top of the stove, in the cookwells?

50-55 pounds of potatoes; 3 roasters; prep the cookpans by coating with non-stick spray and grated Parmesan. Preheat the roasters 20 minutes at 350. Fill the cookwells, put on the cheese, cover and cook away- about an hour if transferred direct from the stove. Check temp with a quick read temp, when it is 180, turn roasters to 180 and leave covered.

Thanks, Ellen. That makes much more sense!
Two questions: I generally use enough liquid to come up just to the top layer of potatoes (i'm thinking no more than 4 inches deep). Is that too much for the roaster. Also, will the potatoes crust and brown as they do in the oven? My experience with these roasters is very limited so
really appreciate whatever you can tell me. I'm sure even not very brown creamy potatoes will taste good, but just want to know what to expect.
The 4 inches is fine. It will not brown as much, but you could run it under the broiler for a few minutes just before serving.