2 cups uncooked egg noodles
1 can condensed cream of mushroom soup, undiluted
1/2 cup milk
¼ cup chopped onion
1 teaspoon prepared mustard
2 cups sauerkraut from the cooler, rinsed and well drained
1/2 pound smoked kielbasa or Polish sausage, cut into 1/2-inch slices
1 cup shredded Swiss cheese
¼ cup soft whole wheat bread crumbs
2 teaspoons butter, melted
Cook noodles according to package directions. Meanwhile, in a small bowl, combine the soup, milk, onion and mustard; set aside. Spread sauerkraut into a 7x11 inch baking dish coated with cooking spray. Drain noodles; place over sauerkraut. Layer with soup mixture and kielbasa; sprinkle with cheese.
In a small bowl, combine bread crumbs and butter; sprinkle over casserole. Bake, uncovered, at 350 deg for 20 to 25 minutes or until brown and bubbly.