Both used Impossible AFAIK (pretty sure they both have them still, too).
> it has a heme protein extracted from soybean roots which gives it that blood smell and taste that is so satisfying.
Glad you like it. Personally, I wish places didn't replace the real veggie burgers with them, but that's mostly a side effect of American restaurants tending to think there should be exactly one veg option so they can't coexist.