01 - Preheat the oven to 300°F (150°C).
02 - Pat the turkey legs dry with paper towels.
03 - Combine olive oil, kosher salt, black pepper, smoked paprika, dried thyme, dried rosemary, minced garlic, lemon zest, and lemon juice in a small bowl.
04 - Rub the marinade evenly over the turkey legs, ensuring full coverage.
05 - Place sliced onion, carrot chunks, and celery chunks in a large roasting pan to create a bed.
06 - Set the marinated turkey legs atop the vegetable bed and pour the chicken broth into the pan.
07 - Cover the roasting pan tightly with aluminum foil and roast for 2 hours at 300°F.
08 - Remove the foil and increase oven temperature to 425°F (220°C). Roast turkey legs uncovered for an additional 15 minutes to develop crispy skin.
09 - Allow the turkey legs to rest for 5 to 10 minutes prior to serving.