Mandy's favorite potato-gratin

• From my dear friend Mandy:  My favorite potato-gratin:
  
  Not really a veg detox recipe, but you can leave out the bacon (and think away the cream ;-))
  
  2 lb. peeled Yukon Gold potatoes
  3 cups whipping or heavy cream
  1 tsp. kosher salt
  1/8 tsp. freshly ground black pepper
  Generous pinch of freshly grated nutmeg
  2 cloves garlic, peeled and smashed
  3/4 cup finely shredded Gruyère
  1/2 red onion
  300 gr bacon
  
  Heat the oven to 400°F. Using a very sharp knife or a mandoline, carefully cut the potatoes into 1/8-inch slices (no thicker). Cut bacon into small pieces and bake until crisp.
  
  Mix the cream, salt, pepper, nutmeg, garlic, and bacon bits. Add a thin layer of this mixture to a large baking dish. Put a layer of potatoes in it, then some onions, and add some of the cream mixture over it. Do the same for a second layer. Make sure all potatoes are covered with some cream. Now, sprinkle the top surface with the cheese.
  
  Bake in the hot oven until the top is deep golden brown, the cream has thickened, and the potatoes are extremely tender when pierced with a knife, about 45-60 minutes. Don't worry if the dish looks too liquidy at this point; it will set up as it cools a bit.