Created by QueenBea on March 17, 2014
Step 1: Preheat oven to 350°F. Pierce the potatoes a few times with a fork. Place directly on the center oven rack and bake until tender, about 1 hour. Let cool slightly.
Step 2: Increase the oven temperature to 450°F. Halve the potatoes lengthwise and scoop out the flesh, leaving a 1/4 inch-thick shell; reserve half of the flesh in a bowl (save the rest for another use). Brush both sides of the potato skins with 2 tbsp melted butter and season with salt and pepper. Arrange skin-side up on a baking sheet and bake until crisp, about 15 mins.
Step 3: Meanwhile, mash the reserved potato flesh with a fork; mix in the cheddar, Muenster, Parmesan, 2 tablespoons of horseradish, and the remaining 1 tablespoon of melted butter. Stuff the potato skins, return them to the oven, and continue baking until golden brown, about 8 minutes.
Step 4: Mix the sour cream with the remaining 1-2 tbsp horseradish. Spoon on the potato skins and sprinkle with the scallions.