Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish. This size helps the cheese brown and the sauce bubble evenly.
Prep the aromatics. If using onion and garlic, heat 1 tablespoon olive oil in a skillet over medium heat.
Sauté onion for 3–4 minutes until soft. Add garlic and cook 30 seconds more. Remove from heat.
Soften the cream cheese. In a large bowl, whisk or beat softened cream cheese until smooth.
If it’s too firm, microwave it for 15–20 seconds to loosen.
Make the sauce base. Stir in the enchilada sauce, sautéed onion/garlic (if using), green chiles, and spices: 1 teaspoon chili powder, 1 teaspoon cumin, 1/2 teaspoon smoked paprika, 1/2 teaspoon salt, and 1/4 teaspoon black pepper. Adjust to taste. The mixture should be creamy and pourable.
Add the chicken. Fold in the shredded chicken until every strand is coated.
If the mixture seems too thick, add 2–3 tablespoons water or chicken broth to loosen.
Layer and top with cheese. Spread the chicken mixture evenly in the baking dish. Sprinkle 2 to 2 1/2 cups shredded cheese over the top. Reserve a little for finishing if you like extra melt.
Bake until bubbly. Place on the center rack and bake 18–22 minutes, until the cheese is melted and the edges are bubbling.
For a golden top, broil on high for 1–2 minutes, watching closely.
Rest and garnish. Let it rest 5–10 minutes to set slightly. Top with chopped cilantro. Add a few dollops of sour cream if you like.
Serve your way. Spoon onto plates as a casserole.
For a heartier meal, serve over riced cauliflower or wrap a scoop in a low-carb tortilla for a “lazy enchilada wrap.”