Cook over a fire (5)
(Other definitions for roast that I've seen before include "Cooked like chestnuts tonight" , "burn?" , "Be uncomfortably hot" , "Heavily criticise" , "Cooked meat; criticise" .)
(Other definitions for chargrill that I've seen before include "Cook with bare flames" , "Cook quickly at a very high heat" , "put on barbecue" .)