01 -
Preheat the oven to 350°F (180°C). Spray a 33 cm x 23 cm (13x9-inch) baking dish with cooking spray.
02 -
In a 20-25 cm (8- or 10-inch) nonstick skillet, heat vegetable oil over medium heat. Cook the chopped onion for 3 to 5 minutes, stirring occasionally, until tender.
03 -
In a medium bowl, combine the cooked onion, cream of chicken soup, sour cream, milk, 1 cup of cheese, 2 tablespoons of ranch seasoning mix, and black pepper. Mix well, then fold in the shredded chicken.
04 -
Arrange half of the frozen tater tots in a single layer on the bottom of the prepared baking dish. Spoon the chicken mixture evenly over the tater tots. Sprinkle 1/4 cup of the cooked and crumbled bacon on top.
05 -
Place the remaining tater tots in a large resealable plastic bag. Add the remaining ranch seasoning mix, seal the bag, and shake to coat the tater tots. Arrange the seasoned tater tots on top of the casserole.
06 -
Bake the casserole in the preheated oven for 40 minutes. Remove from the oven and sprinkle the remaining 1 cup of cheese evenly over the top. Return to the oven and bake an additional 10 to 15 minutes, or until the cheese is melted and the tater tots are lightly browned.
07 -
Remove the casserole from the oven and garnish with the remaining bacon and chopped chives before serving.