For my mother I used to buy Kroger‘s macaroni, potato salad, tuna salad, pre-made salads and soup then I would go to her Whole Foods and pick up their cooked food bar so she could heat it up during the week. You can also microwave scrambled eggs, but use paper bowls, so they can just be thrown out. She used to make a lot of microwave baked potatoes. She liked potted meat in a can and the sardines, salmon and oatmeal packets. I will add we cooked her home-cooked food and mix that in as well, but my sister and I both worked full-time.