Scrub (but don't peel) potatoes and cut into large cubes.
Place cut potatoes in a large Ziploc bag.
Add pesto sauce to the bag and shake until all of the potatoes are coated.
Pour contents out into a baking sheet and spread out evenly. Sprinkle on Parmesan cheese.
Bake for 25-30 minutes, or until potatoes are golden.
Notes
If you want to enhance the flavor of the potatoes even more, you can throw the bag in the refrigerator for a few hours to marinate. It is not necessary for this recipe, but it will definitely enhance the taste.