Preheat oven to 350°F. Lightly oil a 9x13-inch baking dish.
Pat the turkey wings dry with paper towels for better browning.
Stir olive oil, salt, pepper, garlic powder, onion powder, paprika, poultry seasoning, and thyme into a paste.
Rub the seasoning all over the wings until evenly coated.
Spread onions, bell pepper, and garlic in the baking dish. Place wings on top and pour broth around them.
Cover tightly with foil and bake for 60 minutes until nearly tender.
Remove foil, baste with pan juices, and bake uncovered at 400°F for 25–35 minutes to brown.
Rest wings 5 minutes. For gravy, pour pan juices into a saucepan and bring to a simmer.
Whisk flour with a splash of hot pan liquid to make a slurry. Whisk into the saucepan with butter until thickened.
Taste and adjust salt and pepper. Serve wings with onions, peppers, and gravy.