am yisrael chai-
I think this is what you’re referring to:
Go to Google, and in the search box type the text that you’re searching for, followed by “site:www.theyeshivaworld.com/coffeeroom/” sans quotes.
For instance, to find the “flanken kugel” thread, I put the following in the search box, verbatim:
flanken kugel site:www.theyeshivaworld.com/coffeeroom/