Put onion, ham, celery, chicken broth, water, and chicken tenderloins in 6 quart stock pot. With stock pot partially covered bring to a boil, lower heat and simmer for about 15 to 20 minutes or until chicken is cooked through. Remove chicken and set aside.
Add corn, potatoes, milk, thyme, and pepper to pot, salt is optional. Simmer, uncovered until potatoes are tender.
Cut chicken tenderloins into 1/2 inch pieces and return to stock pot.
Thicken soup with cornstarch or flour, adding in 2 tablespoon increments and stirring. Once soup has reached desired thickness let simmer 5 minutes and then serve.
