tian
Synonym discussion
Sense: noun/1
Tian, ratatouille, gratin, and casserole can all appear as oven dishes, but they are not the same. A tian usually features thin slices of vegetables, often tomato, courgette, and aubergine, arranged in neat layers and baked with olive oil. Ratatouille uses many of the same vegetables, yet they are normally cut into pieces and stewed together, so the result is softer and saucier. A gratin is defined more by its browned top, often from cheese or cream, and can be made with potatoes, pasta, or seafood. Casserole is the broadest word: it can describe almost any baked mixture in a deep dish. If the food is layered and vegetable-focused, tian is the best word.
Etymology
Tian entered English from French, where the word names the shallow dish used in southern France for baking vegetables. The vessel name was later extended to the layered vegetable dish cooked in it, so in English tian usually refers to the finished food rather than the pan itself.