Preheat the oven to 400°F (200°C) and line a baking sheet with foil; lightly spray the foil with cooking spray.
In a large bowl, combine the chicken strips, drained black beans, thawed corn, diced avocado, diced green onion, chopped cilantro, and the seasoning mix; toss gently to combine without mashing the avocado.
Lay a tortilla flat and spoon about 1/2 to 3/4 cup of the chicken mixture into the center of each tortilla.
Fold the sides over the filling and roll the tortilla up, tucking in the ends to enclose the burrito.
Place each burrito seam-side down on the prepared baking sheet and lightly spray the tops with cooking spray.
Bake for 10–15 minutes, until the tortillas are lightly browned and crisp.
Serve warm; optional toppings include sour cream and guacamole.