Cheesy Potato and Corn Chowder

(I have left out the green chiles when I don't have them)

2 tablespoons margarine
1 cup chopped celery
1 cup chopped onion
2 (14.5 ounce) cans chicken broth
3 cups peeled and cubed potatoes
1 (15 ounce) can whole kernel corn
1 (4 ounce) can diced green chiles
1 (2.5 ounce) package country style gravy mix
2 cups milk
1 cup shredded Mexican-style processed cheese food (I have used any cheese)

DIRECTIONS
In large saucepan, melt margarine over medium high heat. Add celery and onion; cook and stir until tender, about 5 minutes.
Add chicken broth; bring to a boil. Add potatoes; cook over low heat for 20 to 25 minutes or until potatoes are soft, stirring occasionally.
Stir in corn and chiles; return to boiling. Dissolve gravy mix in milk; stir into boiling mixture. Add cheese; cook and stir over low heat until cheese is melted.