
Preheat oven to 350℉. Heat the olive oil in a large skillet over medium-high heat. Add the onion and cook for 5 minutes until softened and translucent. Stir in garlic and cook for 30 seconds until fragrant.
Stir in the cream cheese, green chiles, salsa verde, and sour cream.
Transfer half of the sauce to a large bowl and add the shredded chicken. Toss until fully coated.
Assemble the enchiladas by spooning ¼ cup of the remaining sauce onto the bottom of a 9x13-inch baking dish.
Spoon about a ¼ cup of the shredded chicken mixture and 2 tablespoons of shredded cheese onto a tortilla, roll it up, and place it in the baking dish seam side down. Continue until all the tortillas have been filled.
Pour the remaining cream cheese sauce on top and sprinkle with the remaining shredded cheese. Cover the baking dish with aluminum foil and bake for 25 minutes, removing the foil halfway through. To brown the cheese, turn on the broiler for 1-2 minutes at the very end.
Serve immediately and top with sour cream, chopped cilantro, and diced tomatoes.