Call the counselor for advice. This surely is not his/her first rodeo. Knowing how other scouts accomplished this before may result in better eats.
P.S. - Keep in mind that even solar/chemical heaters require attention to detail. Too little water (or worse, water that had been chemically purified) and can lead to combustion. Make sure the scouts understand the reaction that is involved and what does or does not go in it. It’s no different really than when we explain the typical fuel-oxygen-heat models. Prepare your scouts for what can go wrong.
Any body else ever start fires with lenses and/or mirrors? Needless to say, solar cookers need to be monitored. Aimed at those kebabs = yum! Aimed at that pile of tinder = move!
Electric? Well, there’s a reason the power company plans black-outs.
I’m not saying to avoid any of these. I am saying that your reply to the scouts needs to be, “Yes, but safely.”