Preheat oven to 375 degrees.Peel turnips and sweet potatoes and cut into small (1/2 inch) cubesGrease 2 large baking sheets with oil and evenly spread the turnips and sweet potatoes on them (Depending on the size of your baking sheets, it may take another baking sheet or a couple rounds to fit them all)Sprinkle with some of the garlic, sage, rosemary, thyme, oregano, turmeric, pepper and salt and toss with your hands.Put into oven and bake for about an hour until they are soft and starting to brown... toss a few times to brown evenly.While those are cooking ... in a large skillet (or Wok) brown the sausage if you are using it.Finely dice the onions, and celery and add to the pan once the sausage has cooked. You might need to add more oil.Dice the mushrooms and peel and dice the apple and add once the onions/celery have started to soften.Continue cooking until all are cooked and add more of the above spices to your taste.Once turnips and sweet potatoes are done, mix with the sausage/onion/celery/apple/mushroom combination and continue mixing until well incorporated and starting to clump together.Transfer to a greased 9x19 baking dish and warm in oven if serving immediately or put in fridge, covered.For reheating: 30 minutes, covered @350 degrees.