2 large sweet potatoes
2 teaspoons fresh thyme, plus extra for serving
1/4 teaspoon sea salt
1/4 teaspoon black pepper
3 tablespoons brown butter, or an equal amount of olive oil (See Recipe Note)
Preheat oven to 375˚F. Wash the sweet potatoes and cut off a small sliver on the bottom of the potato to give it a stable surface. Cut the sweet potato into rough 1/4-inch slices, leaving 1/8 inch intact at the bottom. (You can do this by sight/feel, or by placing chopsticks on either side of the potato and slicing until you hit the chopsticks). Place in a roasting pan.
Strip the leaves from the thyme and carefully tuck the leaves in between the fans of the sweet potatoes. Sprinkle with salt and pepper, then drizzle the brown butter on top, using a brush to spread butter evenly and into the fans as well.
Roast in the oven until the sweet potatoes are soft in the middle and easily pierced with a paring knife, 45 to 55 minutes depending on the size of your sweet potatoes. Serve immediately while hot.