01 - Preheat 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 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 onions and carrots, cooked noodles, condensed cream of chicken soup, sour cream, milk, cheddar cheese, garlic powder, thyme, salt, and black pepper until evenly combined.
05 - Spread the mixture evenly into the prepared baking dish.
06 - Mix crushed crackers with melted butter in a small bowl and sprinkle evenly over the casserole layer.
07 - Bake uncovered for 30 to 35 minutes until hot, bubbly, and topping is golden brown.
08 - Allow casserole to stand for 10 minutes before serving.