"You cook well!"
Translation:אתן מבשלות טוב!
The word טוב is both an adjective (good) and an adverb (well). Here it's used as an adverb, and adverbs are not modified to agree in gender or size.
There is also a word היטב (heitev), which is the technically correct way to translate "well", but for the most part Israelis just say "You cook good!".
Well, I did a cut & paste of the answer & IT DID. But good to know you're checking.