Was Mordechai the mashgiach at Achashverosh's party?

Question

I have seen 2 sources (example) quote a Gemara on Megillah 12a saying that Mordechai was the Mashgiach or served at Achashverosh's mishteh (party). This was very shocking to me. I have tried searching for this Gemara for a while but still have not found it. Can anyone confirm if this is true and it's in the Gemara, and if it's there, what is the exact quote? Thank you

Answer 1

the maharsha and the megilla setarim say that kirtzon ish vaish”....mordechai

means that achashveroah made him the mashgiach mainly for the yayinn nessech issue

Answer 2

Rashi on Megillah 12a says that Mordechai was one of the Butlers of Achashverosh. This is the quote כרצון מרדכי והמן - הם היו שרי המשקים במשתה

Answer 3

You had the right page but the actual gemara itself is not so explicit that he was a "mashgiach.": ״לַעֲשׂוֹת כִּרְצוֹן אִישׁ וָאִישׁ״, אָמַר רָבָא: לַעֲשׂוֹת כִּרְצוֹן מָרְדֳּכַי וְהָמָן. מָרְדֳּכַי — דִּכְתִיב: ״אִישׁ יְהוּדִי״, הָמָן — ״אִישׁ צַר וְאוֹיֵב״. As @Russell points out, Rashi's pshat is that they were the butlers. I can't find other clear sources whether the wine and food were kosher or not. Google turns up a bunch of blogs, drashot, etc without sources saying both ways. I vaguely remember seeing a midrash, probably in the Megillah Shleimah, that the wine was kosher and the food was not kosher, which made everyone unhappy. But I don't have it handy so take with lots of salt.