As a guide, you bake the first 15 minutes at 210 °C/ 425 °F. Then, calculate 20 minutes for every 1 lb or 500 grams of chicken. Of course, the best guide is until juices run clear or the internal temperature reaches 165 °F / 75 °C. Tip - The foolproof method would be to use a meat thermometer. The temperature should reach 165 °F or 75 °C in the thickest part of the thigh or 145 °F in the breast.