Making the Best Scalloped Sweet Potatoes is a simple process when you follow these steps:

1. Preheat the Oven: Preheat your oven to 375°F (190°C) and grease a 9×13 inch baking dish with butter.
2. Prepare the Sweet Potatoes: Peel and slice the sweet potatoes into thin, even rounds (about 1/8 inch thick) for uniform cooking.
3. Mix the Cream Sauce: In a medium bowl, whisk together the heavy cream, minced garlic, thyme, salt, and black pepper until well combined.
4. Layer the Potatoes: Arrange half of the sweet potato slices in the prepared baking dish, slightly overlapping them.
5. Add Cheese: Sprinkle half of the cheddar and half of the Parmesan cheese over the first layer of sweet potatoes.
6. Pour the Cream Mixture: Drizzle half of the cream mixture over the cheese.
7. Repeat Layers: Add the remaining sweet potato slices, followed by the remaining cheeses, and finish with the rest of the cream mixture.
8. Cover and Bake: Cover the dish tightly with aluminum foil and bake in the preheated oven for 30 minutes.
9. Uncover and Brown: Remove the foil and bake for an additional 15-20 minutes, or until the sweet potatoes are tender and the top is golden brown and bubbly.
10. Rest Before Serving: Allow the dish to rest for about 10 minutes to help it set before serving.

By following these steps, you’ll create a delicious side dish that will wow your guests!