Homemade mashed potatoes loaded with cheddar, Gruyère, sour cream and bacon, baked until melty. Boil the potatoes whole so the skins slip right off, and make it the day before Thanksgiving.
Score a circle through the skin around the middle of each potato. Add the whole potatoes to a large pot, cover with water, cover the pot with a lid, and bring to a roaring boil. Cook until tender, about 20-30 minutes depending on the size of your potatoes. Drain and let the potatoes cool enough to handle, then peel off the skins with your fingers. While the potatoes cook, cook the bacon until crisp and crumble it.
In a large bowl, combine half of the shredded cheese with the butter, sour cream, milk, onion dip mix, garlic powder and pepper. Add the warm peeled potatoes and mash by hand to your desired consistency. Taste, and add salt if you like.
Preheat the oven to 400°F and lovingly butter a 9x9 casserole dish. Spread the potato mixture evenly in the dish.
Top with the remaining cheese and the crumbled bacon. Bake until the potatoes are heated through and the cheese has melted, about 5-10 minutes. Top with sliced green onions and serve.
Notes
Make ahead: Assemble through step 4 (cheese and bacon on top), then cover and refrigerate up to 1 day. Keep it in the fridge until it goes into the oven; don't leave it at room temperature for more than 2 hours. Bake it cold from the fridge at 400°F, covered with foil, for 20-30 minutes, until hot in the center (165°F), then uncover and bake 5-10 minutes more until the cheese melts. A doubled batch in a 9x13 dish may need longer under the foil.No onion dip mix? Use 1/2 teaspoon salt plus 2 teaspoons granulated onion for every 2 tablespoons of mix.Cauliflower: Replace some or all of the potatoes with cauliflower, cooked until tender enough to mash smooth.Leftovers: Refrigerate within 2 hours of baking and use within 3-4 days. Reheat until hot all the way through (165°F).Nutrition is for 1 of 8 servings, without added salt.