Preheat oven to 375ºF. Arrange bacon on a slotted broiler pan or on a wire rack set over a baking sheet. Season with black pepper and bake until crisp, 15-17 minutes. Remove from oven and raise heat to 450ºF. Baste bacon liberally with maple syrup and return to the oven for 2-3 minutes to glaze and further crisp the coating.
Meanwhile, place potatoes in a pot, cover with water and bring to boil. Salt water and cook until tender; drain and return to hot pot. Mash with just enough stock to make the potatoes fairly smooth, stir in butter, cheese and thyme, and season with salt, pepper and nutmeg to taste. Top with lots of chopped maple bacon and serve.