I am cooking for one, and I buy in bulk, cook it all at once, and portion it out and freeze, or tray freeze. As I am also in the position of having days when my health makes it difficult to cook, so I have a supply of cooked meals and makings ready. I have also found dairy products like milk, cheese, some kinds of yogurt (not all) freeze well. Some do not. I make a large pot of stew or chili, eat some and freeze the rest in individual containers. I do that with spaghetti too, cook a whole box and add a couple of jars of sauce, eat some and freeze in indivdual containers. Vegetables, roasts, turkey and chicken get the same treatment. Cooking multiple portions at once saves both time and money, and get better food. I also dry some food like banana into banana chips. I can get bananas on sale, eat some fresh and dry the rest for snacks later, and they taste better than the store bought ones, sweeter and fresher.