Cook the egg noodles according to package directions until al dente. Drain and set aside.
In a large skillet over medium-high heat, melt the butter. Add the diced onion, minced garlic, Italian seasoning, and thawed peas and carrots. Season with salt and pepper. Cook, stirring occasionally, until the onions are soft and translucent, about 3-4 minutes.
Sprinkle the flour over the vegetable mixture and stir to combine, ensuring the flour coats the vegetables evenly.
Gradually pour in the chicken broth and heavy cream, stirring continuously to prevent lumps. Bring the mixture to a boil, then reduce the heat to medium-low. Simmer, stirring occasionally, until the sauce has thickened slightly, about 5 minutes.
Add the cooked chicken breast cubes and drained egg noodles to the skillet. Stir gently to combine, ensuring the noodles and chicken are coated evenly with the creamy sauce.
Season with additional salt and pepper to taste, if desired. Serve the One-Pan Chicken Pot Pie Pasta hot, garnished with fresh herbs if desired.