1/2cup chopped onion 
1/4cup butter 
2 Tablespoons flour 
1 teaspoon salt 
1/4teaspoon pepper 
3 cups water 
1-pound fresh mushrooms, sliced 
1 cup chopped celery 
1 cup diced peeled potatoes 
1/2cup carrots 
1-cup light cream (or milk) 
1/4cup grated Parmesan cheese 
 

In a large kettle, sauté onion in butter until tender. Add flour, salt and pepper; stir to make  a smooth paste. 
Gradually add water, stirring constantly.  Bring to a boil; cook and stir for 1 one minute. 
Add the mushroom, celery, potatoes and carrots.  Reduce heat; cover and simmer for 30 minutes or until vegetables are tender. 
Add cream and Parmesan cheese; heat through.