Question:
Inadvertently, a dairy Corelle bowl (which was not used for over 24 hours) was used in heating up a piece of meat (without any liquid, gravy or fat) in a microwave. What is the status of the bowl? Does it need Kashering? And if yes, how?
Answer:
Corelle is considered to be glass, therefore according to the Sefardi minhag the bowl is fine, as they hold that glass does not absorb taste and therefore the bowl never absorbed the taste of the meat. However the Ashkenazi minhag regarding glass is that it does absorb, and it is controversial if it can be kashered at all. The poskim rule stringently regarding pesach, and regarding the rest of the year it is controversial. In your case it is more serious because a bowl that was heated up in a microwave is consider by many poskim as a kli rishon, therefore we would consider the corelle bowl to have absorbed the meat taste, and it should not be kashered. However if the loss of the bowl is significant you can rely on the poskim that hold that you may kasher it.
Sources:
O:CH 451-26, Taz ibid 30, Magen Avraham ibid 49, Emes L'Yackov O:CH ftnt 443, Chut Shani Pesach 10 ftnt. 23, R' Vosner zt"l, Igros Moshe O:CH 5-32(1), Mishne Halachos 9-168.