Heat oven to 350°F Sprinkle chicken with salt, pepper and thyme, inside and out. Loosen skin from breast with and index finger and stuff 2 slices of lemon and 1 tablespoon butter onto each side of the breast. Place remaining lemon in the cavity. Transfer chicken to a roasting pan. Roast 1 hour to 1 hour 10 minutes; basting occasionally. A instant meat thermometer should read 170 in the thickest part of the thigh (not touching bone). Transfer chicken to a cutting board; wait 10 minutes before carving to allow juices to redistribute. Pour off fat from pan. Place pan over 2 burners; pour in chicken broth and bring to a boil. Scrape up brown bits on bottom of pan. Cook 2-3 minutes. Pour over carved chicken.