3 medium sweet potatoes (about 2 pounds total), cut into 1 1/2-inch cubes
2 tablespoons olive oil
1/2 teaspoon kosher salt
1/4 teaspoon freshly ground black pepper
2 cloves garlic, minced
1/4 cup finely grated Parmesan cheese, divided
Arrange a rack in the middle of the oven and heat to 425°F.
Place the potatoes, oil, salt, and pepper in a large bowl and toss to combine. Transfer the potatoes to a rimmed baking sheet and spread into a single layer. Roast for 15 minutes. Flip the potatoes over with a flat spatula and cook until browned and tender, about 10 minutes more.
Remove the baking sheet from the oven. Set the oven to broil. Sprinkle the potatoes with the garlic and half of the cheese and stir to coat well. Sprinkle the remaining cheese over the potatoes. Broil until the cheese is soft and melted, 1 to 2 minutes.
Storage: Leftovers can be stored in an airtight container in the refrigerator for up to 4 days.