Preheat oven to 425°F (220°C) and set aside a large baking dish. In a small bowl, combine cranberries, white wine vinegar, and brown sugar. Stir until cranberries are well coated and set aside.

Place chicken thighs on a clean surface and pat completely dry with paper towels. In a small bowl, mix together paprika, pepper, salt, minced garlic, and olive oil to create a paste. Rub this seasoning mixture all over the chicken thighs, coating both sides. Arrange seasoned chicken thighs in the prepared baking dish and scatter sliced onions around them.

Distribute lemon slices throughout the dish, then spoon the cranberry mixture and any accumulated juices over and around the chicken. Break rosemary sprigs in half and scatter over the entire dish. Pour chicken broth evenly over everything.

Roast for 35–40 minutes, or until chicken reaches an internal temperature of 165°F (74°C) and the skin is golden brown and crispy. Check occasionally to ensure the skin doesn't burn.

Remove from oven and let rest for 5 minutes before serving. Serve over mashed potatoes, rice, or stuffing, and drizzle with pan juices if desired.