Pesto is just a mix of fresh basil, garlic, pine nuts, parmesan cheese, and olive oil. In a blender, I start with a bunch or two of fresh basil, washed and trimmed, 4 cloves of garlic, 1/2 C of grated parmesan cheese, 1/2 C of pine nuts. I pulse the blender a few times, drizzle in olive oil, and resume pulsing. Pulse. Oil. Pulse. Oil.
If you want a smoother, sauce-like pesto, add more olive oil and blend longer; if you want a chunkier pesto, use less oil and blend for less time. So simple. So fresh. So fragrant.
Rinse and pat the potatoes dry. Place them in a roasting pan, drizzle them with olive oil, and cook in a 350 degree oven for about an hour. Once they are fork tender, slice them in half, scoop out some of the meat, and fill the hollow with a dollop of pesto. Serve chilled.