any pasta dishes
make spaghetti and meatballs, make pasta bake, make mac and cheese, alfredo, the possibilities are endless. I'm not saying pasta just because of my name and pfp.
i would also say baked chicken.... you just wash chicken, add seasoning and slap it in the oven then suddenly you have a ton of cooked meat for about 2-3 days to eat with anything
i would say rice but some people think you can cook rice like pasta, theres so many ways to mess up rice without a rice cooker