Can American citizens legally patronize Pyongyang (restaurant chain)?
I am aware that, according to https://en.wikipedia.org/wiki/Tourism_in_North_Korea#Restrictions_and_warnings:
In July 2017, the U.S. government announced that American citizens would no longer be permitted to visit North Korea as tourists. The travel ban took effect on September 1, 2017.
but I don't know whether the U.S. government prohibit American citizens from frequenting businesses owned by North Korean entities.