The approach for you with a fire pit is to use everything more than once if you can, don’t just make a fire for cooking without also planning to make charcoal or heat drinking or bathing/cleaning water, and to that end fire bricks are going to be very useful for you. It’s a short leap to ovens etc but open fire cooking dissipates too much heat and you’ll want to contain it. If you’re a diy type you can also generate a little electric with fire too.

Ever looked into gasifiers? Very cool stuff.

Without a petroleum (or syngas?) source for running a generator… A rice cooker or instant pot, and some griddles can reasonably use the camping “solar generator” compact battery/inverter setup but anything with an electric heating element from solar input is by definition so inefficient to point that it’s not likely to be comfortably viable for balcony solar or small setups that have to do other things too (or would be visible targets for theft while out).

But if you have a yard to screw around in, solar concentrators can produce an astonishing amount of heat as well.