Cheese and Potato Soup

A comfort soup to cheer you up during the winter months.  Cheese and Potato Soup Serves 4 2 tablespoons vegetable oil 1/2 cup celery, diced 1/2 cup chopped onion 1/4 teaspoon dried dill 3 tablespoons all purpose flour 2 cups chicken broth 2 cups milk 1/2 teaspoon mustard powder 4 cups potatoes, peeled and cut into 1 inch pieces, about 4 potatoes 1 cup packed grated sharp cheddar cheese. 1