- olive oil cooking spray
- 4 skinless, boneless chicken strips
- 1 (10.5 ounce) can chicken gravy
- 1 (10.5 ounce) can cream of chicken soup
- 1 cup evaporated milk
- 1 cup sage and onion stuffing mix (such as Pepperidge Farm®)
- 1/2 cup minced onion
- 2 teaspoons minced garlic
- 1/4 teaspoon celery seed
- ground black pepper to taste (optional)
- 1 (32 ounce) package frozen bite-size potato nuggets (such as Tater Tots®)
- 1/2 cup shredded mozzarella cheese
- 1/2 cup shredded Cheddar cheese
- Preheat oven to 375 degrees F (190 degrees C). Spray a 9×13-inch baking pan with cooking spray.
- Heat a large skillet over medium heat. Spray lightly with cooking spray. Add chicken strips; cook until no longer pink in the center and the juices run clear, about 4 minutes per side. Cut into cubes.
- Transfer chicken to a large bowl. Add chicken gravy, cream of chicken soup, evaporated milk, stuffing mix, onion, garlic, celery seed, and black pepper; mix until combined.
- Spread frozen potato nuggets in the bottom of the prepared pan. Pour chicken mixture evenly on top. Sprinkle mozzarella cheese and Cheddar cheese on top.
- Bake casserole in the preheated oven until golden and bubbly, about 45 minutes.