chicken rice soup

2 large carrots, diced
2 celery ribs, diced
1 small onion, chopped
3/4 cup butter (don't think i'll add that much)
3/4 cup flour
1 teaspoon seasoned salt
3 cans (12 oz each) evaporated milk
4 cups chicken broth
2 cups cooked brown rice

Cook carrots and celery to desired tenderness then saute them with onion and butter for 2 minutes. Stir in flour and seasoned salt until smooth. Gradually add milk. Bring to a boil, cook and stir for 2 minutes or until thickened. Gradually add broth. Stir in chicken and rice. Return to a boil. Reduce heat; simmer, uncovered, for 10 minutes.