- Sauté Aromatics 
- Heat butter in a large skillet over medium heat. 
- Add diced onion and garlic, and sauté until softened and fragrant, about 2-3 minutes. 
- Make the Sauce 
- Sprinkle flour over the onions and garlic, stirring to combine. Cook for 1-2 minutes to remove the raw flour taste. 
- Gradually whisk in chicken broth and milk, stirring constantly until smooth. 
- Cook the Noodles 
- Add egg noodles to the skillet, ensuring they are mostly submerged in the liquid. 
- Cover and cook for 8-10 minutes, stirring occasionally, until noodles are tender. 
- Add Chicken and Vegetables 
- Stir in cooked chicken, frozen vegetables, thyme, salt, and pepper. 
- Simmer for 3-4 minutes, or until heated through and the sauce has thickened to your liking. 
- Garnish and Serve 
- Remove from heat and sprinkle with fresh parsley, if desired. Serve immediately.