4 sweet potatoes, peeled and cut into 1 1/2-inch thick rounds
⅓ cup fresh thyme leaves
3 tablespoons olive oil
4 large garlic cloves, minced
½ teaspoon kosher salt
½ teaspoon red pepper flakes
Preheat oven to 450 degrees F (230 degrees C).
Combine sweet potatoes, thyme, olive oil, garlic, salt, and red pepper flakes in a bowl until evenly coated. Arrange coated sweet potato slices in a single layer on a rimmed baking sheet or 9×13-inch baking dish.
Place baking sheet on the top rack of preheated oven; roast until sweet potatoes are tender and slightly browned, about 40 minutes.