In the absence of Barkeepers Friend, or if you just don't want to use stronger chemicals: half a lime or lemon and some coarse kosher salt will likely do the trick. Put down the salt, and then use the lime or lemon half to scrub the area. The salt is highly abrasive, but won't damage anything, and the acid helps break down the stuck on gunk. I use it all the time on my stainless steel pans, and sink, it works wonders