Or perhaps a "spend as little as humanly possible" or "pantry challenge all the time" food budget?
I'd first start by stocking my pantry with essentials to make the cheapest ingredients go the farthest. So I'd want herbs, spices, condiments, oils, and other add-ins to make beans, lentils, rice, and other storage grains taste good. I might also find certain dried or canned or frozen or root-cellared foods essential -- canned tomatoes, for example.
In your pantry, what are those seasonings and essentials, and why do you find them necessary? What meals or recipes would you make (or DO you make) with them on a no-spend or similar budget?
I'm thinking specifically of dinners (with leftovers for lunches) but breakfasts and snacks are also important. My go-to pantry breakfast is oatmeal with cinnamon (and possibly raisins) and snack is scratch popcorn.
If you could stock your pantry with such frugal essentials now, knowing that your grocery budget would need to be as close to no-spend as possible for a number of months, what would you make sure you had in your pantry?