Ham and Noodle Casserole

1/2 package egg noodles, cooked as directed and drained
2 cups cubed cooked ham
1/2 cup chopped onion
1/4 cup butter or margarine
1 8 ounce container sour cream, at room temperatures
4 ounces shredded Swiss cheese
2 eggs, well beaten
2 teaspoons Dijon style mustard

Preheat oven to 350F. Grease a 1 1/2 quart baking dish.

In small saucepan, cook onion in margarine until tender.

In large bowl, combine all ingredients; mix well. Turn into prepared baking dish.

Cover; bake 35 minutes or until hot and bubbly. Remove from oven and uncover.

Bake 5 minutes longer.