1. Pat the chicken dry with paper towels and season with salt.
2. Preheat your Ooni pizza oven to a medium-high heat.
Preheat your Ooni pizza oven to a medium-high heat. If using a conventional oven, preheat to 180˚C (360˚F). You can check the temperature inside your Ooni quickly and easily using the Ooni Infrared Thermometer.
3. Put the olive oil in your Skillet and place the skillet into your Ooni pizza oven.
Note that the Skillet handle will become very hot and should be handled with care – remember to use Ooni Gloves or a dry dish towel and to place the skillet on a heat-proof surface.
4. Remove the hot skillet from the oven.
Place the chicken skin side down onto the hot Skillet, and leave the chicken to sizzle untouched for 3 minutes, or until the skin starts to brown.
5. Once golden brown, flip the chicken over.
Add the butter to the skillet and use a spoon to baste the chicken with the melted butter. Add the rosemary sprigs and onion to the skillet.
6. Return your skillet to the oven to continue cooking the chicken until the chicken juices run clear.