1. To cook the garlic parmesan roasted sweet potatoes: Preheat your oven to 400ºF (200ºC). Peel and cut sweet potatoes into thin slices.
2. Place garlic, oil, butter, salt, Parmesan cheese and Italian seasoning in a Ziploc bag and mix well. Throw in sweet potatoes and shake until well coated.
3. Lightly butter a baking dish and arrange coated sweet potatoes into a spiral. Sprinkle with a little parmesan if you like.
4. Bake sweet potatoes for 30-35 minutes. Serve your garlic parmesan roasted sweet potatoes warm and sprinkle with thyme if desired.
Note: Roasting time will depend on the thickness of your sweet potato slices: the thicker, the longer.