Can this phrasing be used as a more general concept, ie "The bulgogi I've eaten was delicious" - that is, in your experience, all the bulgogi you've had is delicious? Or is it only referring to a single serving you had one time?
The former is unlikely, but possible. "The bulgogi I've eaten was delicious." is now accepted. You would say "제가 먹은 불고기는 다 맛있었어요." to refer to all the bulgogi. Also depending on the context, you'd use -던 instead.