Prep the oven and pan. Preheat your oven to 375°F (190°C). Lightly grease a 9x13-inch baking dish with a little olive oil or nonstick spray.
Sauté the aromatics. Warm 1 tablespoon olive oil in a skillet over medium heat.
Add chopped onion and cook 3–4 minutes until softened. Stir in minced garlic and cook 30 seconds until fragrant.
Build the filling. Add shredded chicken, diced green chiles (or jalapeño), cumin, chili powder, smoked paprika, salt, and pepper. Stir to coat.
Pour in 1/2 cup chicken broth and 1/2 cup tomato sauce. Simmer 2–3 minutes to meld flavors. Stir in 1/4 cup chopped cilantro.
Remove from heat.
Make the quick sauce. In a small bowl or measuring cup, combine the remaining 1 cup tomato sauce with a pinch of cumin, chili powder, and salt. Taste and adjust seasoning. This will be your enchilada sauce layer.
Soften the tortillas. To prevent tearing, warm tortillas.
You can wrap them in a damp paper towel and microwave 40–60 seconds, or lightly toast them in a dry skillet for 10–15 seconds per side. Keep them covered so they stay pliable.
Fill and roll. Spread a thin layer (about 1/3 cup) of the sauce in the baking dish. Place 2–3 tablespoons of chicken filling down the center of each tortilla.
Add a small sprinkle of cheese if using. Roll snugly and place seam-side down in the dish.
Sauce and bake. Pour the remaining sauce over the rolled enchiladas. If using cheese, sprinkle a little over the top.
Cover with foil and bake 15 minutes. Remove foil and bake another 5–7 minutes until heated through and lightly bubbling.
Make the avocado cream. While the enchiladas bake, blend avocado, Greek yogurt, lime juice, garlic, cilantro, salt, and pepper until smooth. Add 1–3 tablespoons water to reach a drizzleable consistency.
Taste and adjust lime and salt.
Serve. Let enchiladas rest 5 minutes. Drizzle generously with avocado cream and finish with fresh cilantro, green onions, and a squeeze of lime. Add crunchy toppings like radishes or tomatoes if you like.