Grease the Air Fryer Basket with cooking spray and then slide inside.
Adjust the temperature of Air Fryer to 300 °F to preheat for 5 minutes.
With a sharp knife, score the leg of lamb at several places.
In a bowl, mix together 2 tablespoons of oil, herbs, garlic, salt, and black pepper.
Coat the leg of lamb with oil mixture generously.
Slide the basket into Air Fryer and set the time for 75 minutes.
Meanwhile, in a bowl, add the Brussels sprout, remaining oil and honey and toss to coat well.
After cooking time is finished, flip the leg of lamb.
Arrange the Brussels sprout around the leg of lamb.
Slide the basket into Air Fryer and adjust the temperature to 390 °F for 15 minutes.
After cooking time is finished, remove the leg of lamb from Air Fryer and place onto a platter.
With a piece of foil, cover the leg of lamb for about 10 minutes before slicing.
Transfer the Brussels sprout into a bowl.
Cut the leg of lamb into desired size pieces and serve alongside the Brussels sprout.