Preheat oven to 375º
Rub a baking sheet with a stick of butter to coat.
Cut slices of bread into bite-size cubes.
Lay bread cubes on prepared baking sheet in a single layer.
Melt butter and whisk in garlic and oregano.
Drizzle over the top of the bread cubes.
Bake for 5 minutes, toss bread cubes with a wooden spoon, continue this method, stirring every 5 minutes until bread is toasted to your desired crispiness or about 15 minutes. Watch closely.
Remove from oven and sprinkle with sea salt.
Reduce oven temperature to 350º.
Combine soup, milk, salad dressing, onion, and mustard in medium bowl; blend well.
Spread sauerkraut in greased 2-quart casserole dish.
Top with cooked noodles.
Spoon soup mixture evenly over top of noodles.
Top with sliced smoked sausage.
Sprinkle cheese over the top.
Cover top of casserole with marble rye croutons. Dot with cubed butter.
Cover pan tightly with foil.
Bake in oven for 45 minutes.
Remove foil, bake 15 minutes more or until hot and bubbly.