2 pounds of small Yukon
Boil the potatoes until just done (a knife will slip easily into the center), drain and return the potatoes to the warm pan. Cover the pan with a clean dish towel and let the potatoes steam until cool enough to handle, about 10 minutes.
Using a paring knife, peel the skins off the potatoes (or you can leave them on if you would like a more rustic dish). Return the potatoes to the pan.
Preheat the oven to 350 degrees. Spray a 2-quart baking dish or 10 6-oz individual ramekins with nonstick cooking spray.
Mash the potatoes, adding in the butter, buttermilk and milk until the potatoes have a smooth, creamy consistency. Stir in the goat cheese and the gruyere cheese, along with the herbs, salt and pepper and mix well.
Turn the potatoes into a 2-quart baking dish (or individual ramekins) that have been sprayed with nonstick cooking spray. Sprinkle the top with a little more gruyere cheese and bake for about 20-30 minutes or until the top is golden brown and the potatoes are heated through. If using individual ramekins, they may be done sooner than that, so check them after 15 minutes.