It is baked in a 9×13-inch casserole dish and perfect for serving as a vegetarian side dish on Thanksgiving, Christmas, Easter, and any holiday and/or gathering!
Preparation: Place one of the oven racks in the center of the oven. Preheat your oven to 375 degrees (190 degrees C). Using unsalted butter, grease a 9×13-inch baking dish.
Heat the half-and-half: In a small-medium saucepan, on the stovetop, heat the half-and-half over low heat until it is simmering and then remove from the heat.
Assemble the casserole: Divide the ingredients into 3rds, layer 1/3 of the potato slices on the bottom of the 9×13-inch baking dish, and add 1/3 onion slices.
Season with a sprinkling of salt and pepper. Repeat the ingredient layers 2 times. Optionally, you can add aromatic seasonings like sage, rosemary, and thyme within the layers.