I love Korean bimbimbap and my favorite has to be Yigah restaurant in Diamond Jamboree in Irvine. I love the fresh mix of cucumbers, carrots, mushrooms, bean sprouts, and greens mixed with beef.
Their banchan (aka small dishes that go along with Korean dishes) are so good. I personally love the spicy radishes and can eat them all day.
Definitely check out this quaint Korean restaurant if you're in the mood for bimbimbap.