Chicken Quinoa Stew - with secret soup ingredient!

My mother-in-law has an eye for finding great recipes in the newspaper or magazines. She found this recipe in the Sunset magazine, and brought it with her and made if for us when we met in Colorado for a ski weekend a couple years ago. It is a keeper! She planned ahead and brought the spices (and quinoa) with her - ingenious, particularly because the ancho chili powder can be a little difficult to find. The ingredient that surprised me the most was the citrus zest. Since then, I've learned that adding a couple slices of orange or lemon can be added to most soups to make it memorable (See "Dull Soup? Fix it with just one ingredient). My other favorite "secret" ingredient to add to soups is shredded cabbage. Add it the last 5 minutes, and wow! You'll be surprised and pleased at the extra flavor (if not the smell in your house), and I always appreciate sneaking in extra veggies wherever I can. This soup pairs well with beer, especially a Gordon Biersch Blonde Bock.

Ingredients

• 4 cups reduced-sodium chicken broth
• 2 pounds boned, skinned chicken thighs
• 2 tablespoons extra-virgin olive oil
• 1 large white onion, finely chopped
• 1 cup chopped ripe plum tomatoes (about 2 large) or fire-roasted diced canned tomatoes
• 2 teaspoons orange (or lemon) zest 
• 1/2 cup quinoa
• 1 cup cooked chickpeas (garbanzos), rinsed if canned
• 1 cup pimiento-stuffed small green olives
• Spices:
• 1/2 teaspoon salt
• 1 t ground cumin
• 1 t ground coriander
• 1 t dried oregano (preferably Mexican)
• 3 garlic cloves, minced
• 1/2 teaspoon ancho chile powder
• 1/2 teaspoon cayenne

Preparation

1. Bring broth to a simmer in a large, heavy-bottomed pot over medium-high heat. Add chicken and lower heat to a simmer. Cook chicken, covered, 15 to 20 minutes, or until cooked through; transfer to a plate. Pour broth into a large bowl and set aside. Wipe out pot.
2. Add oil, onion, and salt to pot and cook over medium heat until onion softens and is starting to brown, about 10 minutes.
3. Stir in cumin, coriander, oregano, and garlic; cook 2 minutes. Add ancho chile powder, cayenne, chopped tomatoes, reserved broth, zest, and quinoa. Reduce heat and simmer, covered, until a white ring appears around each quinoa seed, 10 to 15 minutes. Meanwhile, shred chicken.
4. Add shredded chicken, chickpeas, and olives and heat through.