Preheat your oven to 325°F (160°C) for a low and slow roast that keeps the turkey succulent.
Sauté the chopped onions in butter (or oil) in a large Dutch oven over medium heat until soft and fragrant.
Add the turkey to the pot, nestling the pieces into the onions to help release those smoky aromas.
Layer the cabbage wedges directly on top of the turkey, filling the pot to the brim (it will shrink significantly as it cooks!).
Whisk the broth with the garlic powder, onion powder, and red pepper flakes, then pour it over the cabbage to keep everything moist.
Cover tightly and roast in the oven for 1.5 to 2 hours until the cabbage is perfectly tender and the turkey is falling off the bone.
Gently toss the pot halfway through the cooking time to ensure the smoky, buttery juices coat every leaf.
Serve hot in shallow bowls, making sure to include a generous ladle of the savory "pot liquor" from the bottom of the dish.