Tortellini con Beschiamella

This is a family favorite recipe that we got from the Richaels.  I always double the recipe because it goes quick!

1/4 cup butter
2 T. flour
1/2 tsp. salt
2 cups milk
dash nutmeg
1/2 cup ham, chopped
1 14-16 oz pkg of frozen cheese tortellini

For sauce:  In a saucepan over medium heat, melt butter.  Add flour, salt, and nutmeg and stir just until bubbly.  Slowly add  milk.  Over medium heat, bring to boil, stirring constantly.  Boil for 1  minute and remove from heat.  Add ham.  Pour sauce over cooked tortellini and serve with grated Parmesan cheese