- Sweet potatoes. I eat one almost every day. I live in NC and can buy bulk local-grown ones in the fall and they last a very long time, but even at the grocery store it's only like 1.50 for 3 good sized ones. Eat them cooked in oven at 400, wrapped in foil for 1.5hrs depending on size, with butter or just salt.
- Sardines - I just eat from the can or over toast. Can also be good mixed with mayo. Lots of good deals available here, but try to prefer Morroco or Poland sourced ones vs the bottom tier ones from China. Bonus is sardines are lower in mercury than bigger fish like tuna.
- Goat cheese from Aldi - It's like $2/8oz there, my regular store is more than double that
Then I pair it all up with toast. The toast part isn't very healthy, but it's cheap.
I don't have a real cost reason to prefer cheap eating, but I'm the kind of person who would happily eat the exact same meal my whole life if given the option. So it's fun to optimize a little.