I don’t think it’s a US American thing per se. Refried beans are a common staple of Mexican dishes and may incorporate lard (as will more authentic flour tortillas). They’re mashed, not whole beans.
And while I wouldn’t use them in tacos, canned baked beans like those you’d find in the UK may also not be vegetarian.
Lots of beans have lard or pork in them.
Is this a joke I’m not American enough to understand?
I don’t think it’s a US American thing per se. Refried beans are a common staple of Mexican dishes and may incorporate lard (as will more authentic flour tortillas). They’re mashed, not whole beans.
And while I wouldn’t use them in tacos, canned baked beans like those you’d find in the UK may also not be vegetarian.
The word tacos implies Mexican food, and Mexican preparations of beans traditionally use lard as the cooking fat.