My green flags of choice are Seo Gongmyung (played by Park Sung Hoon in Into the Ring opposite Nana) and Suganami Kotaro (played by Kentaro Sakaguchi in Okaeri Mone).
Bon Appetit isn't anything new or original but it's hella fun nonetheless. It's just so typical Kdrama-y. It doesn't disappoint a bit and surprisingly the two leads have a really good chemistry despite the age gap.
/s
Check the Okaeri Mone links.