Combine milk and cornstarch in a saucepan; stir well. Place over medium heat; bring to a boil and cook 1 minute, stirring constantly. Remove from heat. Gradually stir about 1/4 of hot milk mixture into yolks; add to remaining hot milk mixture, stirring constantly, and cook 1 minute.
Add Monterey Jack cheese, mustard, paprika, and salt, stirring until cheese melts. Add bleu cheese, crumbled; stir well. Put mixture into a large bowl; set aside.
Beat egg whites in a large bowl at high speed of an electric mixer until stiff peaks form; gently fold into cheese mixture. Pour into a 1-quart souffle dish coated with cooking spray. Bake at 350 degrees F for 28 minutes or until puffed and golden. Serve immediately with warmed fresh slices of crusty bread.