Enchiladas topped with cheese and filled with deliciousness.
Rub chicken thighs with 1 tablespoon olive oil, garlic powder, oregano, half the salt, and half the black pepper. Heat lightly greased grill or grill pan to medium-high heat. Grill chicken thighs 7 to 8 minutes per side. Chicken is done when it feels firm to touch and meat thermometer inserted in center reaches 170 degrees F. Remove from heat, let rest 2 to 3 minutes, and shred.
In a saucepan, heat remaining 1 tablespoon olive oil. Sauté chopped onions until soft. Add chili powder, cumin, hot sauce, cinnamon, and remaining salt and black pepper. Add tomato sauce and simmer 10 to 15 minutes until flavors are well blended.
Spoon 1/3 cup of the enchilada sauce into 9-by-13-inch glass baking dish. Toss shredded chicken with enough tomato sauce to moisten. Microwave the tortillas for 10 to 15 seconds to soften. Place generous spoonful of chicken, 1 tablespoon Monterey Jack, and 1 tablespoon Cheddar onto softened tortilla and roll up. Place enchiladas seam side down in one layer snugly inside baking dish. Pour the remaining sauce over enchiladas. Sprinkle with remaining Monterey Jack and Cheddar.
Heat oven to 350 degrees F. Bake enchiladas until cheese melts and starts to brown, about 20 minutes. Remove from oven, garnish with chopped cilantro, and serve with sour cream on the side, if desired.