01 - Preheat the oven to 375°F and 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 of butter in a large skillet over medium heat and 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 black pepper.
05 - Spread the combined mixture evenly into the prepared baking dish.
06 - Combine crushed crackers with melted butter and evenly sprinkle over the casserole.
07 - Bake uncovered for 30 to 35 minutes until the casserole is hot, bubbly, and the topping is golden brown.
08 - Allow to stand for 10 minutes before serving to set.