My child’s baby sitter by accident melted cheese on noodles in one of our Pyrex glass bowls that are used for meat. Do I need to throw it out?
If the noodles were not heated up in the bowl itself but only put in afterwards, (melting the cheese by placing it on to the hot noodles), then the bowl my still be used. You would only have to wash the bowl out well, with soap with water the isn’t hot.
However I am assuming that the noodles were actually heated up in the Pyrex bowl, making the bowl a kli rishon. Pyrex is a type of glass and there are different minhagim is it may be kashered or not. The Sefardi minhag (who go like the opinion of the Mechaber) is that it glass dos not absorb taste and therefore never needs kashering, therefore it may be used again after it is washed out well. The Ashkenazi minhag however is a matter of controversy, some poskim say that it can be kashered, while other say that it can’t. Even according to those who say that glass cannot be kashered, there are numerous poskim who say that Pyrex can be kashered since it is strong and there is no fear that it will break under the intense heat of kashering it. You may rely on these poskim and kasher it. Wash it well so that it is totally clean, then boil a pot of water and after it is bubbling well, insert the bowl inside it for a few second, then remove it and rinse it in cold water. If the bowl is too big to fit into a pot there is another option. Fill the bowl with water until the top and bring it to a bubbling well, then insert something that is hot, (such as a rock that was heated on the fire), and place it inside the bowl while it is boiling so that the water flows over the top so that top of the bowl will be in contact with the boiling water.
Rema O:Ch 451- 26, Magen Avrohom ibid 49, Eliyahu Rabba ibid 54, and Y:D 87-2, Chayei Adom 125-22, Igros Moshe O:CH 5-32(1), MInchas Shlomo 2-50 D:H Hienei, Chelkas Yackov Y:D 45, Tzitz Eliezer 8-20 (6), Yisodei Yishurun 6 pg. 168