I have a problem with sichuan peppercorns...or at least, I believe that to be the cause. When I eat a dish containing it, like Sichuan cold rabbit, I get this unpleasant metallic taste in my mouth that stays for hours. (I get the same problem from Belon oysters). Is this really the cause of the metallic taste? Or is it another ingredient? I have a recipe I'd like to try, but I think I'd prefer to substitute black or white peppercorns.