“name phở could have come from pot-au-feu”

Didn’t know that. The French also make consommé which is a very luxurious, very clear beef broth. I prefer Bun Bo Hu, but it’s not as easy to find good examples, even in my area.

Traditionally, you spend a lot of effort on clear broth. You can, toward the end, add egg white only to remove it once it accumulates protein from the broth.