1. Coat a 2 1/2-quart casserole dish with nonstick cooking spray. Spread half of the potatoes over the bottom of the dish. Top with half of the apples, half of the carrots, and, finally, half of the prunes. Repeat the layers.
2. In a small bowl, combine the orange juice, honey, brown sugar, orange rind, and potato starch, and stir to mix. Pour the orange juice mixture over the tzimmes. Cover the pan with foil, and cut four 1-inch slits in the foil to allow steam to escape.
3. Bake at 350°F for 1 hour and 15 minutes, or until the layers are tender.