Preheat oven to 375 degrees.
In a large bowl, combine the rice, chicken, salsa, cumin, chili powder, paprika, onion powder, and garlic powder.
Place parchment or aluminum foil on a large baking sheet.
Place peppers on the lined baking sheet.
Divide chicken mixture between peppers, and top with cheese.
Bake for 15-20 minutes, or until cheese is golden brown.
Top with cilantro and, if desired, Greek yogurt.
Serve immediately.