Step 1

Preheat oven to 350°F with rack 6 to 8 inches from heat source. Coat a 7- x 11-inch baking dish with cooking spray; set aside. Heat oil in a large skillet over medium-high. Add bell peppers, poblano, and onion; cook, stirring occasionally, until softened and starting to char in spots, about 5 minutes. Add green chiles with juices, fajita seasoning, garlic, and ½ teaspoon of the salt; cook, stirring constantly, until fragrant, about 1 minute. Remove from heat; stir in chicken. Set aside.

Step 2

Stir together cream cheese, 1 cup each of the white Cheddar and smoked Cheddar, and remaining 1 teaspoon salt in a large bowl until thoroughly combined. Add chicken mixture, and stir together until combined.

Step 3

Transfer mixture to prepared baking dish; sprinkle evenly with remaining ½ cup each white Cheddar and smoked Cheddar. Bake in preheated oven until mixture is bubbling and cheese has completely melted, about 25 minutes. Increase oven temperature to broil; broil until cheese starts to brown, 4 to 5 minutes. Remove from oven; let cool about 10 minutes. Sprinkle evenly with cilantro. Serve immediately with desired toppings.