It's putting it mildly to say that Han Lee is a fairly regressive portrayal. To begin, he speaks with a broken, generically Asian accent, and then moves on to nicely tick off basically every possible Yellow Panic stereotype with an actually fairly impressive level of thoroughness. For real, it's distressingly easy to imagine the writers sitting around yelling out listing off every single ching-chong stereotype, ultimately deciding with some sorrow that a Fu Manchu mustache would be impractical for budget reasons. Or rather, it would be, except that would obviously be far too much time spent fleshing out this character. A tiny, greedy, sexless man-child… The pervasive crime of Han Lee really boils down to his infantilized speech patterns, thrown in, I assume, just in case his Asian face didn't drive the message that He Is Not Like You home enough, and you were starting to think of him as some kind of human being.
Congrats to show creators Michael Patrick King and Whitney Cummings!