From Longman Dictionary of Contemporary Englishgratingrat‧in /ˈɡrætæn $ ˈɡrɑːtn/ noun [countable, uncountable] a dish containing vegetables or fish, covered in cheese or cheese sauce and cooked in an oven
Examples from the Corpus
gratin• In a gratin dish pour a little of your cream sauce.• The gratin dish should be quite full. 