01 - Preheat oven to 375°F. Grease a 9x13-inch baking dish with butter or cooking spray.
02 - Cook egg noodles in salted boiling water until just al dente, about 7 minutes. Drain well and set aside.
03 - In a large skillet over medium heat, sauté onions, carrots, and garlic in a splash of oil for 4–5 minutes until softened.
04 - In a large bowl, whisk together cream of chicken soup, sour cream, milk, chicken broth, cheddar cheese, thyme, salt, and pepper until smooth.
05 - Add cooked chicken, sautéed vegetables, frozen peas, and drained noodles to the sauce. Stir until evenly coated.
06 - Transfer the mixture to the prepared baking dish and spread into an even layer.
07 - In a small bowl, combine breadcrumbs, Parmesan, melted butter, and parsley. Mix until butter coats crumbs evenly.
08 - Sprinkle crumble mixture evenly over the casserole. Bake uncovered for 30–35 minutes until golden brown and bubbly.
09 - Let the casserole rest for 5–10 minutes before serving to allow flavors to set.