Jen I've no idea why the instructions always say that about the liquid, it's usually far too much.
Cubed beef or pork, tossed in a little flour mixed with ground ginger, makes a nice starting point for a casserole.
You tend to need quite a lot of flavouring to get the best results.
Re gammon, yes leave it on as you would normally, and agree with mm, an inch or so of liquid is fine