An important thing is the reasonably smoke-tight seal for the lid!
I've heard of folk doing that sort of thing in (old) woks and casseroles - with tight fitting lids...
You may want to have
- a container for the smokestuff (sawdust, tea, ...)
- a rack for the food being smoked
- a means of preventing the food dripping onto the smokestuff (a tray under the rack, above the smokestuff?) Some folk might think you should have some water there for added humidity...
I'm sure I heard of someone using two identical roasting tins, one as the base, the other as the lid. I'm afraid I can't recall how they were clamped together...
Some folk think that a single roasting tin and lots of aluminium foil is all you need...
http://www.uktvfood.co.uk/index.cfm?ukt ... iID=516206