In a large stock pot or dutch oven, melt butter over medium high heat. Add onion, celery, and carrot. Stir occasionally and saute until they start to brown and are fragrant. Add garlic, stir, and cook for another couple of minutes.

Add chicken broth, bay leaves, and thyme. Continue to heat to bring the soup to a simmer. Just before it boils, remove from heat and add noodles, parsley, lemon, and cooked chicken. Noodles will cook in the hot broth. Add salt and pepper, to taste.