Prick each of the potatoes in a few places and bake at 400 degrees for 1-1 1/2 hours or until soft. Remove the potatoes from the oven and allow them to cool for 15 minutes. Meanwhile, in a non-stick skillet, saute the red onion and shallots in the olive oil for 5-7 minutes or until soft. Add the diced apple and saute an additional 3-4 minutes or until the apple is tender. Remove the skillet from the heat and set aside. Lightly oil (or spray with a light mist of oil) a large casserole dish and set aside.
When the potatoes are cool to the touch, cut each one in half lengthwise, and use a spoon to scoop out the inside of the cooked potatoes into a bowl while keeping the potato skin shells intact. Place the potato skin shells in the greased casserole dish and set aside. Using a fork or potato masher, mash the cooked potatoes to desired creaminess. Add the reserved apple mixture, parsley, sage, dry mustard, salt, and pepper, and stir well to combine. Taste and adjust the seasonings as needed. Evenly divide the mashed potato filling among the potato skin shells. Using a fork, rake the surface of the filling, and then sprinkle 2 T. of the shredded soy cheese over each one. Bake the filled potatoes at 400 degrees for an additional 15 minutes or until the cheese is well melted and bubbly.
Serves 8