Preheat oven to 350 degrees. Spray an 11 x 14 inch baking dish with non stick cooking spray; set aside.
Mix together olive oil, kosher salt, onion powder and garlic together; brush over the surface of the chicken pieces on both sides. Place the chicken into the baking dish, cover with foil and cook for one hour.
Meanwhile, make the sauce by whisking together the orange juice, orange sections, orange zest, brown sugar, ancho chile powder, cornstarch and parsley in a medium saucepan; bring to a simmer and cook 15 minutes then remove from heat; set aside.
Remove chicken from oven and drain off the liquid. Spoon the orange sauce mixture over the chicken and return to oven, uncovered, for 15 minutes or until tender.
Add the sweet potatoes to a large saucepan or dutch oven, cover with water and simmer until nearly fork tender or about 8 minutes. Drain the water off and using the same saucepan, add the olive oil and bring to medium low temperature. Saute the red bell pepper, onion, celery and jalapeno pepper for 3 minutes. Stir in the sweet potatoes. Cook, stirring for five minutes; stir in the apples, ginger, salt, white pepper and brown sugar. Continue to cook potatoes, stirring to evenly caramelize, for 15 minutes.
To serve, spoon potatoes onto a platter topped with the chicken. Spoon any sauce over the top and sprinkle with toasted walnuts. Garnish with chopped cilantro.