For the Sauce: Place the onion and garlic in a food processor and blend until a liquidy paste forms. Scrape the sides a couple times during the process.
Place a saucepan on medium-high heat.
Add oil, onion/garlic mix and saute for five minutes until all the liquid has cooked off.
Add the enchilada sauce, salsa verde, sugar, salt and pepper and cook for another 5 minutes.
Add the minced cilantro, taste and add more salt and pepper if needed.
After ten minutes, turn the heat off and set the sauce aside.
For the Enchiladas: In a large bowl, place all the shredded chicken, 1 cup of shredded cheese and ½ cup sauce and mix well. Taste mixture and season with salt and pepper, if needed.
Create assembly line of ingredients to make enchiladas: stack of tortillas, clean plate for sauce-soaked tortillas, salsa verde sauce, shredded chicken mix, bowl with remaining 2 cups shredded cheese and baking dish for enchiladas.
Add ½ cup sauce to coat the bottom of 9 x 13-inch baking dish.
Dip the corn tortillas in the sauce to soften, one at a time, and place onto a clean dish.
Take a sauce-soaked tortilla, add chicken mix, carefully roll and place into baking dish, seam side down. Repeat until all the enchiladas are made.
Add the remaining sauce to the top of enchiladas. With your hands, carefully push down on the enchiladas to submerge under the sauce.
To finish, add remaining 2 cups of the cheese to cover the enchiladas and sauce. If you like, add black olives or whatever fun topping you desire before baking.