the other way of doing it is to stand the can upright in boiling water, put two little holes in the lid and boil for about 15 mins, bit like boil in the bag really. Same again and use water for brew. Tip: when you stand the can in the water, try to expel the air bubble from under the can, improves the way the food is heated.
we used to live on these things in the 80s, hexy and messies, i can smell the bacon grill from here