Been thinking of how I used to heat and cook food before the days of 24v microwave ovens and the gas rings commonly in use today, how long I left a well wrapped tin foil pork chop or even bit of steak or pork pie or any other etc. jammed between the exhaust ports of my old Bedford TK to be cooked or heated up while on the road.
Who else done has this?
In my day, six or eight of us used to meet up in Moscow or Istanbul or somesuch and cook “Camion Stew” 
Must admit to cooking bacon & eggs in the heat on top of someones aluminium fuel tank once!
bbq’s with anything handy,started with just a metal grid and worked upto shopping trollies etc.
great banter with other drivers but now days everyone sits behind closed curtains. 
bedford tks a mobile kitchen, exhaust manifold designed to lay the foil wrapped gear in safety. ready and waiting when you stop, brilliant. and a water boiler jubilee clipped onto the passenger grab handle. also being 5ft 4in sleeping bag on parcel shelf. ready and waiting to travel anywhere.
A mate and I once cooked tins of soup on a fire we made from a pallet, I reversed the trailer over the pallet to break it up into little pieces and dipped a few bits in the diesel tank to get the fire going, then stabbed a hole in the top of the cans with a screwdriver and rested them in the fire.
This was not out of necessity because we were stuck up a mountain somewhere, although we were in a little village in Italy, it was because we were both totally ■■■■■■ and it seemed like a good idea at the time, upon reflection it was a silly idea, you can wear gloves to protect your hands from red hot cans, but lips are a different story, especially when the booze wears off and the real pain starts 
The parcel shelf was very handy in the TK, proper sleeper cab !! but one very cold night the piece of cardboard I had stuck to the side window fell off and in the morning my feet were numb for ages through touching the glass, and no night heater in them, or the truck. Brrrrr