In 4-quart Dutch oven cook onions in hot oil over medium heat for 5 to 10 minutes or until tender. Whisk together milk and flour; add to onions. Cook and stir 5 minutes.
Add potatoes and chicken broth. Bring to boiling; reduce heat. Cover and cook for 20 minutes or until potatoes are tender. Remove from heat; cool slightly.
Puree soup, half at a time, in blender. Return to Dutch oven; add shredded cheese. Cook and stir over medium heat just until cheese is melted. Season to taste with salt and pepper. Sprinkle fresh herbs; garnish with sliced cheese. Serve at once. Makes 8 (1 cup) servings.