To salvage her disgraced career, an L.A. Chef goes to work for a Kdrama star whose temper is as challenging as the cuisine.

So it seems that the Kdrama celebrity is the antagonist. But the plot is vaguely stated. (happens in over 50% of the posted loglines on this site -- so you are not alone).

Maybe try something like the following: have the Kdrama star host an LA exclusive culinary event in which all of the top LA chefs will attend (including former employers of the MC). Now the difficult Kdrama celebrity, with poor food ideas, is standing between the MC and his/her redemption.

Or something along those lines.

Hope: MC wins acclaim and redeems career,
vs.
Fear: following the bimbo celebrity's bad food ideas will result in culinary humiliation and flopdom in LA.

Kick-it up a notch: Food Network will televise the event so flopdom extends to the entire country!

Specifying that character as a Korean Soap star would help clear up the confusion with the original lolgline description.
However that is a small problem compared to the much larger one of the plot being mostly absent.

good point - I don't want to make anyone google - but I think part of the sell is the Korean crossover... should I say Korean soap star?