Preheat and prep: Heat your oven to 375°F (190°C).
Grease a 9x13-inch baking dish with olive oil or butter.
Sauté aromatics (optional but recommended): In a skillet over medium heat, add a little oil. Cook the onion and bell pepper with a pinch of salt until softened, 4–5 minutes. Stir in the garlic for 30 seconds.
Remove from heat.
Make the creamy taco sauce: In a mixing bowl, combine cream cheese, sour cream, tomato paste, taco seasoning, and chicken broth. Whisk until smooth. Taste and adjust salt, pepper, or seasoning.
Combine the filling: In a large bowl, add shredded chicken, sautéed veggies, green chiles, and 1 cup of shredded cheese.
Pour the sauce over and mix until everything is coated.
Assemble the bake: Spread the mixture evenly in the prepared baking dish. Top with the remaining 1 cup of cheese.
Bake: Place in the oven for 18–22 minutes, until the edges are bubbling and the cheese is melted.
Broil for color (optional): Switch to broil for 1–2 minutes to brown the top slightly. Watch closely so it doesn’t burn.
Rest and garnish: Let the bake rest 5–10 minutes so it sets.
Top with cilantro, green onions, sliced jalapeño, and diced avocado if you like. Serve with lime wedges.
Serve ideas: Spoon into bowls with a side salad, pile onto shredded lettuce, or serve with low-carb tortillas or cheese crisps for scooping.