I think he means what excretes when you fry onions.
Yes, it's all the onion has to offer.
Ę̵̚x̸͎̾i̴͚̽s̵̻͐t̷͐ͅe̷̯͠n̴̤̚t̵̻̅i̵͉̿a̴̮͊l̵͍̂ ̴̹̕D̵̤̀e̸͓͂t̵̢͂e̴͕̓c̸̗̄t̴̗̿ï̶̪v̷̲̍é̵͔
I think he means what excretes when you fry onions.
Yes, it's all the onion has to offer.