In a mixing bowl, whisk together the heavy cream, minced garlic, salt, and black pepper.
Layer half of the sliced potatoes in a baking dish. Pour half of the cream mixture over the potatoes and sprinkle half of the grated Gruyere cheese on top.
Repeat the layers with the remaining potatoes, cream mixture, and Gruyere cheese.
Cover the baking dish with foil and bake for 40 minutes. Remove the foil and bake for an additional 20 minutes, or until the top is golden and bubbly.
Let the casserole cool for a few minutes before serving.
Notes:
This dish pairs well with a simple green salad or roasted vegetables.