I mean if I was out backpacking I would just not even bother to cup meal, take a good source of nuts for protein (Pistachios are my absolute favourite). And a decent range of fruits. I personally favour ties oranges/tangerines and nectarines, as they simply burst with juice is an incredible flavour. But whatever works for you. Obviously if you are back at buttfucking for a number of days you may need a wider nutrient profile, but if it’s just a one day journey out then I think you can just get your daily nutrients in the most simple form.
If you do wanna take out a more cooked recipe, then I’m a big fan of pasta dishes, you can packet incredibly dense vegetables into the source, and reduce it down to make it thick and incredibly rich, and then adding carbohydrates in the form of pasta to give you energy.
Take it out in a plastic container, and it can be eaten hot or cold.