3 pounds sweet potatoes, peeled and sliced into 1/8 inch rounds
2 cups heavy cream
1/2 cup vegetable broth
3 cloves garlic, minced
1 tablespoon fresh thyme leaves, chopped
1 tablespoon fresh rosemary, finely chopped
1 teaspoon sea salt
1/2 teaspoon black pepper
1 cup shredded parmesan cheese
2 tablespoons unsalted butter, softened
Instructions
Start by preheating your oven to 375 degrees Fahrenheit. Grease a 9×13 inch baking dish generously with the softened butter to ensure nothing sticks. Using a sharp knife or a mandoline slicer, carefully slice your peeled sweet potatoes into uniform rounds about 1/8 inch thick. Keeping the slices even is the secret to making sure everything cooks at the same rate.
In a medium mixing bowl or a large measuring cup, whisk together the heavy cream, vegetable broth, minced garlic, chopped thyme, rosemary, salt, and black pepper. This liquid will infuse every layer of the potatoes with savory, aromatic flavor as it bubbles away in the oven.
Arrange about one third of the sweet potato slices in the bottom of your prepared baking dish, overlapping them slightly like shingles. Sprinkle a small handful of the shredded parmesan over this layer. Repeat this process with the remaining potatoes and cheese, ending with a final layer of potatoes on top. Pour the cream mixture evenly over the entire dish, ensuring the liquid settles between the layers.
Cover the baking dish tightly with aluminum foil. Place it in the center of the oven and bake for 40 minutes. Covering the dish allows the potatoes to steam and become perfectly tender without the top browning too quickly.
Carefully remove the foil and sprinkle any remaining cheese over the top. Bake for another 15 to 20 minutes, or until the cream has thickened and the top is beautifully golden brown and bubbling. Let the dish rest for at least 10 minutes before serving. This resting period is crucial as it allows the sauce to set so you get clean, beautiful helpings.
