Pine Street Market in Portland is a lot like what you envision. In typically Portland fashion it is a little on the fancy side and priced somewhere between fast food and pub fare but still reasonable in my book. Food cart culture in PDX somewhat emulates canteen style dining too.

http://www.pinestreetpdx.com/

The Parts Unknown Nashville episode also had a good look at cafeteria style dining that you may enjoy.

https://explorepartsunknown.com/nashville/when-all-you-need-...

I personally would love such an establishment in my small city.