Debone your cooked rotisserie chicken, shredding the meat as you go. Or boil chicken breasts and shred.
Fill a large pot with 8 cups water (use water from boiling breasts), add 5 tablespoons chicken soup base or bouillon. Bring to a boil making sure all the soup base dissolves.
Add noodles and cook for 8 to 12 minutes until the noodles are soft.
Add 1 Tablespoon minced dried onion. Add in shredded chicken.
Reheat to a simmer but do not boil. At this point, you can keep on the stove on low until ready to eat or for up to an hour.
Serve over mashed potatoes.