Preheat the oven to 400°F. Line a large baking sheet with parchment paper for easy cleanup and to prevent sticking.

Place the sweet potato cubes in a large bowl and set aside. In a small bowl, combine the olive oil, garlic, and thyme, then pour this mixture over the sweet potatoes. Toss to coat evenly with the oil and seasonings.

Arrange the sweet potatoes in an even layer on the baking sheet. Spacing them out ensures the potatoes roast evenly and don’t steam.

Roast in the preheated oven 20-30 minutes, stirring halfway through. They’re done when they’re fork-tender and golden brown on the edges. (Exact cooking time will depend on the size of your diced potatoes.)

Remove from the oven and sprinkle the roasted sweet potatoes with parmesan and fresh parsley while they’re still hot. Serve warm or room temperature.