This was on Voat.co like a week ago. Answer is beans and rice.

However, if you are clever, you can also make a large batch of broth/soup on the cheap, buying cheap meat (it will all fall apart in the broth/soup, so bones and fat aren't an issue) and stock flavour is fairly cheap. Chicken wings are a good idea, as they have plenty of flavour and meat for the cheap price. Any fat will settle on the top and is easily scooped off. Bones are easily picked out when serving. Any meat with bones still in them are cheaper than the cuts, so this can be done with beef, pork, lamb etc. Vegetables added would be potato, carrot, celery, etc.

Cooked right, this can be enough for 2 weeks. However, this recipe does take a day to make, mainly to allow it to settle and for the meat to become soft enough to fall off the bones. If anyone is curious, I can type it up, as this is a good alternative to the usual rice answer.