01 - Set the oven to 350°F (180°C) on fan mode or gas mark 4.
02 - Combine softened butter, parsley, thyme, rosemary, lemon zest, and minced garlic in a bowl to create the herb butter.
03 - Pat turkey crown dry with paper towels. Gently separate the skin and spread half of the herb butter underneath. Rub the remaining butter evenly over the top surface.
04 - Brush the turkey crown with olive oil and season thoroughly with sea salt and black pepper.
05 - Arrange lemon halves, quartered onion, chopped carrots, and celery in a large roasting tray. Place the turkey crown breast side up on top of the vegetables.
06 - Pour 1 cup of chicken stock into the base of the roasting tray to keep the environment moist.
07 - Roast for 1 hour 45 minutes, basting every 30 minutes with pan juices. Cover loosely with foil if the skin browns too quickly.
08 - Verify the thickest part of the breast registers 165°F (74°C) to ensure doneness.
09 - Remove from oven and rest loosely covered with foil for 20 minutes before carving.