Cream of Chicken Soup

This is my favorite soup. It takes a little time--but is really easy.

4 Chicken Breasts baked, colled and cut into pieces
1 med onion chopped
1 cup carrots chopped
1 cup celery chopped
2 cups potatoes chopped
2 cans of chicken broth (I just cook my chicken in water and us the broth)
Simmer ingredients (except chicken) with a lid for about 20minutes, or until vegetables are cooked.

Then in a seperate pan combine:
3/4cup margarine
2/3 cup flour
Stir together over medium heat for 2-3 minutes, then add:
1 quart warm milk
1/4 tsp pepper
1 tsp. sale
1/2 tsp. sugar

Stir together with wire wisk until thick. Add vegetable mixture (do not drain) to milk and cook till the flour is cooked out. Add chiken last. If it gets too thick, thin with broth or milk.