Vegetable cooking spray
1 1/2 c. chopped onion
3 tbsp. all purpose flour
1/2 tsp. dry mustard
1/4 tsp. salt
1 1/4 c. skim milk
1/2 c. low sodium chicken broth
1 1/2 c. shredded reduced fat sharp cheddar cheese
3/4 c. shredded Swiss cheese
1/2 tsp. pepper
1 c. non fat sour cream alternative
1 (32 oz.) frozen southern style hash browns, thawed
Paprika

Coat a medium saucepan with cooking spray; place over medium heat until hot. Add onion and saute 3 minutes or until tender. Add flour, mustard and salt; stir well and cook additional minute. Remove from heat; gradually add milk and broth, stirring with a wire whisk until blended. Cook over medium heat 5 minutes or until thickened, stirring constantly. Remove from heat; add cheeses and pepper, stirring until cheeses melt. Stir in sour cream.

Combine cheese mixture and potatoes; stir well. Spoon into a 13"x9"x2" baking dish coated with cooking spray. Sprinkle with paprika. Cover and bake at 350 degrees for 35 minutes. Uncover and bake an additional 35 minutes.