1-First, prepare all ingredients by shredding the 2 cups of cooked chicken breast, dicing the large yellow onion, and mincing the 3 cloves of garlic. This pre-measuring step, including the 1 cup of chicken broth and 1 cup of heavy cream, helps everything move quickly and reduces stress during cooking.

2-Second, cook 12 ounces of egg noodles according to the package instructions until they are al dente. Once done, drain them and set aside to keep their texture intact for mixing later.

3-Third, in a large skillet, melt 2 tablespoons of butter over medium heat and add the diced onion, minced garlic, and 1 ½ cups of thawed frozen mixed vegetables. Sauté until the onion is translucent, then season with 1 teaspoon of dried thyme, salt, and pepper for that classic flavor.

4-Fourth, stir in 2 tablespoons of all-purpose flour to create a roux, cooking it for 1-2 minutes while stirring constantly to avoid lumps.

5-Fifth, gradually whisk in the 1 cup of chicken broth and 1 cup of heavy cream, simmering until the sauce thickens to a creamy consistency.

6-Sixth, add the shredded chicken and sautéed vegetables to the sauce, stirring to combine and heat through.

7-Seventh, mix the cooked egg noodles into the sauce, ensuring everything is evenly coated. Taste and adjust seasoning with salt and pepper as needed.

8-Eighth, for any adaptations, make substitutions during the relevant steps, like using vegan butter in the sautéing stage.

9-Finally, serve the dish hot, garnished with 2 tablespoons of chopped fresh parsley if desired. This step ensures the flavors are at their best, and you can enjoy it right away alongside a green salad for a complete meal.