I saw a fairly shallow aluminium frying pan is Asda the other day. It was only about ?5 but the inside was Teflon non stick. I nearly bought it, and may yet go back, just for cooking BIR dishes. The non stick coating probably won't do any harm and if it all comes off as a result of high flames, then so what? I'll be left with a 100% aluminium base. Something else I would consider is using sandpaper or wire wool to remove the non-stick coating either from the outset or soon after I notice it breaking up , if it ever does.