01 - Preheat oven to 375°F. Grease a 9x13-inch baking dish.
02 - Cook egg noodles in a large pot of salted boiling water until just al dente. Drain and set aside.
03 - Melt 2 tablespoons butter in a large 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, cream of chicken soup, sour cream, milk, shredded cheddar, garlic powder, thyme, salt, and black pepper until well combined.
05 - Spread the mixture evenly into the prepared baking dish.
06 - In a small bowl, mix crushed crackers with melted butter. Sprinkle evenly over the casserole.
07 - Bake uncovered for 30 to 35 minutes until hot, bubbly, and the topping is golden brown.
08 - Allow casserole to rest for 10 minutes before serving.