A gratin also spelled gratinée or au gratin is a crispy crust on top of a dish.
Furthermore, the gratin is a French culinary technique that uses potato, macaroni, breadcrumbs, and grated cheese as toppings. Today, it has become a dish of its own. Frequently referred to as gratin dish.
From those definitions, we can derive the following rules:
1. Usually, people bake and/or broil a gratin in a shallow dish.
2. By tradition, the topping is cheese or breadcrumbs, and they should become crispy under the broiler.
3. The word “Gratin” has its origins in the French verb gratiner, to broil. Furthermore, some people link it to the
French word “grater,” which means to scrape or grate as in the gratings of bread and/or cheese.
4. Gratin has many different forms.
Every culinary tradition has an interpretation of gratin. You can mistake it for other dishes since it has evolved a lot.