Why don't you try Let's Eat? Goo Dae Young fits your bill especially towards the latter part of the drama. :)

Also, I know you're only looking for taiwanese and korean dramas but you should also tryOrange Days. It's a classic j-drama and I think you're gonna love Kai. :)
You have to try The Greatest Love! It has everything you described. It's one of my favorites and I see we have similar tastes :) Just don't judge it by it's first episode, give it a bit more time :)