The apartment complex we live in recently banned gas grills on all but the first floors so we had to give up ours. A few months ago I bought the White Box Stove over the internet and have tested it a few times boiling water, it's like a soda can stove only sturdier. It runs on denatured alcohol and is small enough to be easily tossed in a backpack and should be adequate for two. I grew up around campfires and wood stoves so if wood was available I would improvise a setup with that as well.

(BTW while trolling the net I did come across aluminum dutch ovens)