If a Sephardic orders a piece of meat/fish in a restaurant and by accident forgot to tell the rabbi to put the food on the grill, is it asur to eat it Bc of bishul akum?

A – You can rely on sfek sfeka.
Maybe like the rema that its enough that a Jew turned on fire, maybe its good when the goi works for you or when he is at your premises. (Chacham Ovadia)
Q – this only applies to Jewish owned establishments though, right?
A – True