01 - Preheat the oven to 375°F. Grease a 9x13-inch baking dish.
02 - Boil egg noodles in salted water until just al dente. Drain and set aside.
03 - Melt 2 tablespoons unsalted butter in a skillet over medium heat. Sauté chopped onion and diced carrots for 4 to 5 minutes until softened.
04 - In a large bowl, mix cooked chicken, peas, sautéed onion and carrots, cooked noodles, condensed cream of chicken soup, sour cream, milk, shredded cheddar cheese, garlic powder, dried thyme, salt, and black pepper until thoroughly combined.
05 - Spread the mixture evenly into the prepared baking dish.
06 - Combine crushed crackers with melted butter, then sprinkle evenly over the casserole mixture.
07 - Bake uncovered for 30 to 35 minutes, or until the casserole is hot throughout and the topping is golden brown.
08 - Allow the dish to stand for 10 minutes before serving to set.