from The Century Dictionary and Cyclopedia
- (verb) To cook in a rich sauce and cover with a crust of browned crumbs.
Yes, there is such a word as gratinate and it means to cook with a covering of grated cheese or buttered breadcrumbs - or both. You are right in saying that in current American use, the phrase 'au gratin' means invariably 'with cheese topping.'
Le Gavroche is famous for its souffle suissesse, which is a gussied-up version of the ordinary cheese variety, removed from the oven partway through baking, transferred to a gratin dish full of double cream, topped with grated cheese and then put back to gratinate.
The farfalle gratinate, too, was full of flavor and texture. Pieces of mushroom, chicken and ham melded with butterfly noodles and was topped by a light crust of cheese.
‘Gratinate’ comes from the French ‘gratin,’ crust.