au gratin
adjective /əʊ ˈɡrætæn/
/əʊ ˈɡrætn/
[usually before noun] (from French)- covered in breadcrumbs or cheese and made brown by heating in an oven, etc.
烤面包：用面包屑或奶酪覆盖，并在烤箱中加热等制成褐色。 词源French, literally ‘by grating’, from the verb gratter ‘to grate’.