Making Chicken and Dumpling Casserole can be done with these easy steps:

1. Preheat Oven: Begin by preheating your oven to 375°F (190°C).
2. Prepare Chicken Mixture: In a large bowl, combine the shredded chicken, cream of chicken soup, chicken broth, milk, and frozen mixed vegetables. Add garlic powder, onion powder, thyme, salt, and pepper. Mix until combined.
3. Transfer Mixture: Pour the chicken mixture into a greased 9×13 inch casserole dish, spreading it evenly.
4. Make the Dumplings: In another bowl, whisk together the flour, baking powder, and salt for the dumplings. Stir in melted butter and milk until a soft dough forms.
5. Drop Dumplings: Using a spoon, drop spoonfuls of the dumpling mixture onto the chicken mixture in the casserole dish. Make sure to space them out evenly.
6. Bake: Place the casserole in the preheated oven and bake for 30-35 minutes, or until the dumplings are cooked through and lightly golden on top.
7. Check for Doneness: To ensure the dumplings are done, insert a toothpick in the center of the dumpling; it should come out clean.
8. Cool Slightly: Once baked, allow the casserole to cool for about 5 minutes before serving to let the flavors settle.

These straightforward steps will guide you in preparing this delicious casserole with ease, allowing you to focus on enjoying the meal with loved ones.