Heat your oven to 350 degrees. Rinse the potatoes and chop them into small even pieces, about 1 inch in size. It's really important that the potatoes are pretty even in size so that they cook evenly.

Place the diced potatoes in a bowl. Melt the butter in the microwave, and pour it over the potatoes. Add the olive oil, salt, pepper, thyme, and 2 tablespoons of the Parmesan. Toss together.

Arrange the potatoes in a single layer on a baking sheet. Roast the potatoes for 30 minutes at 350 degrees.

After 30 minutes, stir the potatoes, add another tablespoon of Parmesan on top, reduce the heat of the oven to 225 and let the potatoes roast for another 45 minutes.

Serve the potatoes right away.