Preheat the oven to 400°F and line a baking sheet with foil or parchment paper. Scrub the skin of the sweet potatoes thoroughly.
Use a very sharp knife to make several vertical cuts from the top of the sweet potatoes most of the way through, stopping about ¼ inch from the bottom. Place the sweet potatoes on the baking sheet.
Brush with the melted ghee and sprinkle the sea salt on top.
Roast for 60 to 75 minutes, until the sweet potatoes are soft.
While the sweet potatoes are in the oven, in a small bowl, combine the ghee, garlic, rosemary and thyme. Stir well with a spoon until it forms a soft mixture.
Top the hot roasted sweet potatoes with the compound ghee.
