Preheat oven to 400 F.
Spray a 9 x 9 baking dish with nonstick spray. Evenly arrange sliced potatoes in dish.
In a medium sized saucepan, heat the milk, cream, garlic and 2 T of the chives together over medium heat until simmering. Slowly crumble in the goat cheese, whisking constantly, until the mixture is creamy and smooth. Season with salt and pepper.
Pour the cheese mixture over the potatoes and sprinkle with the remaining tablespoon of chives.
Bake for 40-45 minutes, until the top is browned but the potatoes are still creamy. Let sit for 5-10 minutes before serving.