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