Layers of potatoes are flavored with sweet, thinly sliced onion rings and bathed in milk or half and half. The traditional ingredient in these classic potatoes is flour. The potatoes benefit from the flour and milk mixture, since it becomes a creamy sauce as the potatoes bake. The onion layers provide a sweet undertone of flavor. These are first cooked covered to allow the potatoes to slowly steam and soften and then finished uncovered so a crust can form.
You will have an even creamier result if you use baking potatoes (russets, often called an Idaho potato) since they take on a softer texture during cooking. This hearty potato casserole can be served in a variety of ways.
There are a number of excellent slicing tools available. You can use the Oxo V-Blade Mandoline Slicer or the Microplane Hand-Held Adjustable Slicer, the slicer blade in your food processor or you can slice them by hand with a heavy kitchen knife. I like to have the potatoes sliced and the filling ready to assemble so it only takes a few minutes to put together.
If you are a crust lover, remember that a shallow baking dish actually cooks more evenly and allows for much more topping than a taller dish. So here is a hint for all of you crust lovers. Look for a shallow baking dish for any gratins you may cook so that there is more area on top for a crusty topping.
- Look for potatoes that are firm, smooth-skinned and dark brown. Make sure there is no green discoloration on the potato.
- Keep potatoes in a cool, dark place, and make sure you remove the plastic bag; otherwise, they will go bad very quickly.
- Choose other favorite melting cheeses like Fontina, Gouda or Comte, if you are adding cheese.
- 1 medium garlic clove, minced
- 3 tablespoons all-purpose flour
- 1 1/2 teaspoons salt
- 1/8 teaspoon white pepper
- 3 pounds medium yellow or white potatoes, peeled and thinly sliced
- 1 small onion, thinly sliced
- 1 cup shredded Gruyere cheese, if desired
- 3 tablespoons unsalted butter
- 3 cups whole milk or half and half
- 2 tablespoons finely chopped parsley, for garnish
1. Preheat an oven to 350 F. Spray a 9-by-13-inch ovenproof casserole dish with olive oil. Combine the garlic, flour, salt and pepper together in a small bowl and mix to combine.
2. Arrange 1/3 of the potatoes on the bottom of the dish and then sprinkle with 1/2 of the onions. Sprinkle 1/2 of the flour mixture on the onions. Sprinkle with1/3 cup of grated cheese. Dot with one tablespoon of butter. Make another layer exactly the same way. Layer with the last third of the potatoes, the last third of the cheese and dot with the remaining tablespoon of butter. Pour over the milk or half and half and cover with foil.
Place the casserole on a baking sheet.
3. Bake for 50 minutes. Remove the foil and continue baking another 45 minutes or until the top is golden brown and the potatoes are tender. Remove from the oven, sprinkle with the parsley and serve immediately.