Mashed Potatoes with onion

1 pound potatoes 1 pound apples, granny smith or other tart variety 1/2 teaspoon salt 2 slices bacon cut into 1/4 inch pieces 2 each onions or one large 2[...]

6 Yukon Gold potatoes, peeled and quartered 5 slices bacon 1 tablespoon vegetable oil 6 medium mushrooms, sliced 1 medium onion, sliced 2 tablespoons butter 2[...]