- 1 (12 ounce) package frozen mixed vegetables (carrots, corn, peas)
- 2 tablespoons butter, divided
- 1/2 onion, chopped
- 1/2 cup sliced celery
- 1 tablespoon all-purpose flour
- 1 cup chicken broth
- 2 cups cubed cooked chicken
- 1 teaspoon seasoned salt, or to taste
- 1 pinch cayenne pepper, or to taste
- ground black pepper to taste
- 1 cup sour cream
- 1/2 cup shredded mozzarella cheese
- 1 sheet prepared pastry dough
- Place a steamer insert into a saucepan and fill with water to just below the bottom of the steamer. Bring water to a boil. Add frozen vegetable mix, cover, and steam until tender, 2 to 6 minutes.
- Preheat oven to 350 degrees F (175 degrees C).
- Melt 1 tablespoon butter in skillet over medium heat; cook and stir onion and celery in hot butter until soft and translucent, 5 to 10 minutes.
- Melt remaining butter in a pot over medium-high heat. Whisk flour into butter to form a thick paste. Slowly add chicken broth to flour-butter mixture, whisking constantly, until mixture is hot and slightly thickened, about 5 minutes.
- Stir chicken, steamed mixed vegetables, and onion-celery mixture into broth mixture; season with seasoned salt, cayenne pepper, and black pepper. Remove from heat and let mixture cool slightly, about 5 minutes.
- Fold sour cream and mozzarella cheese into chicken mixture; pour into a casserole dish.
- Spread pastry dough over the top of the chicken mixture and pierce the dough several times with a fork.
- Bake in the preheated oven until crust is browned and chicken mixture is bubbling, about 30 minutes.