Step 1

Arrange a rack in the middle of the oven and heat the oven to 425°F. Peel the sweet potatoes if desired and cut crosswise into 1-inch-thick rounds.

Step 2

Place the rounds on a rimmed baking sheet. Drizzle with the butter (or ghee or coconut oil), sprinkle with the salt, and toss to coat. Arrange in a single layer, with at least 1/2 inch between the rounds.

Step 3

Roast for 20 minutes. Using tongs, flip the rounds, then roast for 20 minutes more.