Bring to a boil water to cover and simmer, covered, until tender:
Drain. When cool enough to handle, remove the skins and mash the potatoes in a large bowl. Heat in a large skillet over medium-high heat until the foam subsides:
Add and cook, stirring until the vegetables are tender, about 5 minutes:
Add and cook, stirring, until the apples are tender but still firm, 3-4 minutes:
Stir into the sweet potatoes, along with:
Adjust the seasoning and moisten, if needed, with:
Dot with:
Use as a stuffing or turn into a large shallow buttered baking dish and bake in a 350 ° F oven until browned and bubbly, 30-45 minutes.