This creamy casserole is a comforting and flavorful side dish, perfect for anyone seeking a satisfying and wholesome meal. It features a delightful blend of textures and savory notes. This dish can easily be incorporated into a weeknight dinner, appealing to a wide range of palates.

While this casserole is often enjoyed casually, its roots trace back to the classic Potatoes au Gratin, also known as gratin dauphinoise, a celebrated French dish dating back to the late 1780s. Traditionally, it consists of thinly sliced potatoes baked with cream and cheese, creating a rich and indulgent experience. The term "gratin" refers to the culinary technique of topping a dish with a browned crust, which in this case, is achieved with cheese.

Today, numerous variations of this beloved dish exist, including this take on "potatoes" au gratin that utilizes a clever alternative to keep things lighter. While cauliflower, zucchini, and squash are often used in low-carbohydrate versions, this recipe aims to stay true to the original potatoes au gratin experience by featuring turnips. Turnips are an often-overlooked vegetable that work exceptionally well in this recipe.

They closely resemble potatoes in appearance and possess a similar taste and, with the right preparation, can mimic their texture and bite. Raw turnips can have a slightly sharp and bitter taste that some might find off-putting. However, in this au gratin, that strong turnip flavor is minimized by boiling the sliced turnips for about 10 minutes, helping to soften their texture and mellow their flavor.

The recipe calls for grated mozzarella and cheddar cheese, but the dish is versatile and can be customized to your liking. Gruyere, parmesan, provolone, or pecorino Romano would all work beautifully, imparting their own unique flavors and textures to this comforting and adaptable casserole.