Preheat the oven to the temperature specified on the steak fry package. Line a large rimmed baking sheet with parchment paper or foil for easy cleanup.
In a large bowl, toss the frozen steak fries with 1 tablespoon of the Cajun seasoning. Spread them out in a single layer on the prepared baking sheet. Bake according to package instructions, adding 5 to 10 extra minutes if you like them extra crispy.
While the fries are baking, heat olive oil in a medium skillet over medium heat. Add the chicken pieces and season with the remaining 1 tablespoon of Cajun seasoning. Cook, stirring occasionally, until the chicken is browned and cooked through to an internal temperature of 165°F, about 6-8 minutes. Remove from heat.
In a small bowl, whisk together mayonnaise, sour cream, milk, hot sauce, and garlic powder until smooth. Set aside.
Once the fries are golden and crispy, remove them from the oven. Evenly top the fries with the cooked chicken and shredded Monterey Jack and Cheddar cheeses.
Return the baking sheet to the oven and bake for 5 to 7 minutes, or until the cheese is fully melted.
Drizzle the creamy hot sauce over the fries. Garnish with chives and a few extra dashes of hot sauce if desired.
Serve immediately while hot and melty.