Cut the chicken breast into ½" cubes by placing the chicken on a cutting board and slice the breast into ¼" slices. It is best to use a chef's knife for this. Then cut each slice crosswise into cubes.
Melt butter over medium heat in a 6-quart pot or dutch oven. Add the onion, celery, and carrots and cook until tender, stirring often.
Add the cubed chicken to the pot, season with salt and pepper, and stir. Cook this mixture for about 5 minutes to brown the chicken.
Pour the chicken broth over the chicken and vegetable mixture. Bring the mixture to a boil. Turn the heat to low and simmer until the chicken reaches 165 degrees and is no longer pink. About 20 minutes. You do not want this mixture to boil.
Turn the heat back to medium and stir in the noodles and corn, and cook until noodles are tender about 10 minutes. Stir occasionally.
Taste the broth and adjust the salt and pepper as needed, and serve.
To store the leftover soup, transfer the soup to an airtight container, leave the cover off and let it cool for an hour. Place the uncovered container in the refrigerator until completely cooled, then cover it. This soup will keep for 4 days.
Reheat the soup by reheating on the stove, or in the microwave.