This English dish, also called Lancashire Hotpot, traditionally consists of meat, usually lamb, covered by alternating layers of thinly sliced potatoes and onions and baked with stock. This version of Lancashire Hotpot is... made with layers of sliced apple, onion, and potato. By leaving out the meat, this dish becomes a very delicious side that goes with virtually anything.
Preheat the oven to 400 degrees. Lightly grease a 13 x 9 x 2-inch baking pan with a lid. If you do not have a lid, use aluminum foil lined with parchment paper to create a lid. Set aside.
Heat the olive oil in the wide skillet over medium heat. Add the onions and saute until translucent, about 5 to 7 minutes. Sprinkle with salt and pepper, then stir in the rosemary and cider vinegar. Raise the heat to medium-high and cook, stirring occasionally until the onions begin to brown, about 7 to 10 minutes. Be careful not to let the onions burn. Let onions cool slightly.
In a bowl, toss the sliced potatoes and apples with the onion mixture, and sprinkle with some salt and pepper.
Lay the potatoes and apples evenly in the prepared baking pan. Dot with butter, cover, then bake for 25 minutes or until the potatoes are tender. Uncover, then continue to bake for 10 minutes or until well browned on top. Serve.
Be sure to use waxy potatoes like Yukon Gold to make this. It won’t work as well with Idaho or Russet potatoes. They are too starchy and soft.