Onion Cream Soup with Mozzarella

I developed this recipe when I once had an abundance of sweet onions. I like making it for guests, but sometimes I'll halve the recipe and make some just for me.

2 cups onions, thinly sliced
½ cup butter, cubed
¼ cup all-purpose flour, unbleached
2 cups chicken broth
2 cups milk
1½-2 cups part-skim mozzarella cheese, shredded
sea salt
black pepper, freshly ground

To Serve:
croûtons

In a large saucepan, cook onions in butter over low heat until tender and transparent, about 20 minutes. Stir in flour. Gradually add broth and milk; cook and stir over medium heat until bubbly.

Cook and stir for 1 minute longer; reduce heat to low. Add mozzarella cheese and stir constantly until melted (do not boil). Season to taste with salt and pepper. Serve with croûtons if desired.

Nutritional Information:
Per 1 cup serving: 294 calories, 23g fat (14g saturated fat), 66mg cholesterol, 600mg sodium, 12g carbohydrate (7g sugars, 1g fiber), 11g protein