Heat oven to 350°F.
Spray 8-inch square ceramic or broiler-proof baking dish with cooking spray.
Heat a medium size skillet over medium-high heat. Add olive oil and onion; cook 5 minutes or until onion is soft.
Reduce heat to low. Add quinoa, chicken, black beans, green chiles, and the enchilada sauce; stir to combine. Remove from heat.
Stir in cheddar cheese. Transfer quinoa mixture to prepared baking dish. Top evenly with Mozzarella cheese.
Bake 10 to 15 minutes.
Turn oven control to broil and broil 1 to 2 minutes or until cheese is golden and bubbly. Remove from broiler. Top with sour cream and cilantro. Serve immediately.