Preheat the oven to 375 degrees F (190 degrees C).
Place sweet potato cubes in a bowl. Drizzle coconut oil over potatoes and toss, using your hands, until each cube is coated. Spread sweet potato cubes onto a baking sheet; season with rosemary, thyme, salt, and pepper.
Bake in the preheated oven until potatoes are softened, about 20 minutes.