Preheat your oven to 400°F (200°C).

Peel the sweet potatoes and slice them into thin discs, about ¼ inch thick.

In a large resealable bag, combine sweet potato slices with olive oil, melted butter, minced garlic, grated parmesan, salt, pepper, and Italian seasoning. Seal the bag tightly and shake until well-coated.

Lightly butter your baking dish and arrange the coated sweet potato slices in a spiral pattern. Sprinkle fresh thyme on top.

Roast the sweet potatoes in the preheated oven for 30-35 minutes until tender and golden brown.

Remove from the oven and allow to cool for a few moments before serving warm.