Combine shredded chicken, 1/2 cup pico de gallo, 1/2 cup sour cream, 1/2 cup Mexican cheese blend, and taco seasoning in a large bowl.
Spray a baking dish with cooking spray. Fill each pepper with as much chicken mixture as possible and place in the baking dish. Sprinkle pepper halves with 1/4 cup Mexican cheese blend. Cover with olives and remaining 1/4 cup cheese.
Bake in the preheated oven until cheese is melted and peppers have begun to soften, 15 to 20 minutes. Top each cooked pepper with a dollop of pico de gallo and sour cream.
For a spicier nacho bite, substitute jalapenos for the mini bell peppers.
You can make your own taco seasoning with 1 teaspoon chili powder, 1/2 teaspoon seasoned salt, 1/8 teaspoon oregano, 1/8 teaspoon red pepper flakes, 1/8 teaspoon ground black pepper, 1/8 teaspoon garlic powder, 1/8 teaspoon onion powder, 1/8 teaspoon cayenne powder, and 1/8 teaspoon cumin.