Easy Chicken and Dumplings

3 celery ribs, chopped
1 cup sliced carrots
1/2 cup chopped onion
1-2 tablespoons olive oil
3 (14.5 ounce) cans chicken broth
salt & pepper to taste
3 cups cooked, cubed chicken
2 cups Bisquick
2/3 cup milk

In a large pot or dutch oven, saute celery, carrots and onion in 1-2 tablespoons olive oil for 5 minutes.  Stir in the broth (I added 2 more cups of broth to the 3 cans), salt and pepper, and chicken.  Bring to a boil.  For dumplings, combine biscuit mix and milk.  Drop by tablespoons into boiling broth.  (Push down with back of spoon if needed.)  Cover and simmer for 10-15 minutes or until a toothpick inserted in dumpling comes out clean (do not lift cover while simmering).