You can partially cook rice / pasta / potatoes, then take your pot off the stove, wrap it in a towel / blanket or sleeping bag, making sure the pot is not glowing otherwise whatever you used will have an individual design mark. Everything will still cook as long as you don't open the lid.
How long you need to cook things is a bit of an experiment
.With rice I have managed to cook it for 5 minutes and then just leave it to soften up. But depends on the typeof rice and how much heat your stove gives .
If you cook pasta : When it is half done, you can add your veggies tomatoes etc and boil down the water
so that you get a thick sauce, saving on simmering the sauce separately. You will probably get a soupy sauce / soggy pasta the first time round, but afterwards you will know exactly your timing.
Not sure if you are atthe dock
at the moment, but if you have access to mince/ground meat, you can cook a whole lot with basics like onion,tomato salt
and pepper reserve half ,cook the other half as bolognese for example and the next day make for example a risotto with the cooked mince/ground meat.