When groceries are low I love doing breakfast for supper, I always have the stuff on hand to make homemade pancakes. Omelettes are good too, you can throw in a hodgepodge of pretty much anything. Grits are cheap and filling.
And there is nothing like a good ole PB&J. I like Nature's Own Light Honey Wheat, regular PB & sugarfree jam...I can fill my belly, get some a little healthy grain and oil and satisfy a sweettooth for about 200 calories.