Heat the oven: Preheat to 375°F (190°C). Lightly grease a 9x13-inch baking dish.
Sauté the veggies: Warm oil in a large skillet over medium heat.
Add onion, bell pepper, and zucchini. Cook 5–7 minutes until softened. Stir in garlic and cook 30 seconds more.
Mix the sauce: In a bowl, combine enchilada sauce, tomato sauce, chipotle (if using), chili powder, cumin, smoked paprika, oregano, and a pinch of salt and pepper.
Taste and adjust seasoning.
Make it creamy: Whisk sour cream and cream cheese into the sauce until smooth. This keeps the bake rich and helps it set without tortillas.
Combine with chicken: Add shredded chicken to the skillet with veggies. Pour in half of the sauce and toss until evenly coated.
Layer the bake: Spread half of the chicken mixture in the baking dish.
Sprinkle with one-third of the cheese. Add the remaining chicken mixture on top.
Add sauce and cheese: Pour the remaining sauce over the top and finish with the rest of the cheese.
Bake: Place in the oven for 18–22 minutes, until the sauce bubbles and the cheese is melted with lightly golden spots.
Rest and garnish: Let it rest 5–10 minutes so it sets. Top with cilantro, green onions, and jalapeño if you like heat.
Serve: Spoon into bowls and finish with sliced avocado and a squeeze of lime.
Enjoy as is, or add a simple side salad or cauliflower rice.