I stumbled across a variation of this roasted potato idea one day when I was cooking for a few vegetarian friends. I took pre-cooked potatoes, green onions, corn and almond milk with a touch of spicy mustard. Wrapped them in parchment paper and cooked it en Papillote style. It was the "hit" of the meal.
I'm curious. Finding it hard to picture for some reason. What function does the milk serve? Does it make a sauce?