Potato cheese soup

4 potatoes, peeled and quartered
1 small carrot, finely chopped
1/2 stalk celery, finely chopped
1 small onion, minced
1 1/2 cups vegetable broth
1 teaspoon salt
2 1/2 cups milk
3 tablespoons butter, melted
3 tablespoons all-purpose flour
1 tablespoon dried parsley
1 teaspoon ground black pepper
1 cup shredded Swiss cheese

In a large saucepan, bring potatoes, carrots, celery, onion, vegetable broth and salt to a boil. Reduce heat; cover and simmer until potatoes are just tender. Do not rinse: mash mixture slightly. Stir in milk. In a small mixing bowl, blend butter, flour, parsley, and pepper; stir into potato mixture. Cook and stir over medium heat until thickened and bubbly. Remove from heat: add cheese and stir until cheese is almost melted. Let soup stand for 5 minutes.