In a large skillet over medium heat, fry the bacon until crispy. Remove the bacon to a paper towel to drain. Add the olive oil to the bacon grease. Put in the onion and saute until translucent. Add the brussels sprouts, salt and pepper. Stir and allow the brussels spouts to caramelize. Add the chicken stock and cover with a lid. Cook until sprouts are tender (about 15 min.) Uncover and allow the rest of the liquid to evaporate out and remove from heat. Pour the brussels sprouts into a dish. Gently stir in the orange zest and the orange juice. Top with crumbled bacon pieces. Ummm good!