Preheat the oven to 425°F (220°C).
In a bowl, combine the chicken, olive oil, Dijon mustard, honey, garlic, salt, lemon zest, and oregano. Mix well. Marinate in the refrigerator for at least one hour (preferably overnight).
Set up either a vertical spit or set an onion in a baking dish and insert two skewers, vertically.
Remove the chicken from the refrigerator. Thread each piece of chicken onto the skewers, rotating their position so they stack well.
Cut a small piece of tin foil and place it over the top of the stack so the top piece of chicken won’t burn. I move the foil around to cover any pieces that look like they are getting too charred.
Place the spit in the oven and add a cup of stock to the base. This will become the sauce. Keep an eye on the base, as you may need to add additional stock if it dries up.
Bake for around 80-100 minutes, until the chicken reaches an internal temperature of 160°F (71°C) (it will continue to rise in temperature while resting). Mine took about 100 minutes. I removed the foil from the top about 10 minutes before it was done so the top could get some char.
Take it out of the oven and baste it with the juices that have run off. Let it rest for 5-10 minutes before basting again, and slicing.