Drain and rinse the sour kraut well, set aside.
Heat a non stick pan and melt 1-2 tablespoons of butter, when hot, add the onion. Saute the onion, adding butter as needed, until the onion is softened and turning golden brown. Set the cooked onion aside.
While the onion is cooking, add the whole sausage to a pot and cover with water. Bring to a boil and cook until the sausage is heated through, about 5-10 minutes after the water starts boiling.
Place the sausage on a cutting board, slice into coins about ½ inch thick, then cut each slice in half.
Using the same or another pot, add enough water to cook the egg noodles, lightly salt and bring to a boil, when boiling, add the egg noodles and cook until tender. Drain water from the pot leaving the noodles in the pot.
Add the ¼ cup butter and mix in until melted, then stir in the Parmesan, onions, salt, pepper as desired, and a pinch or two of poppy seeds.
Drain the sour kraut again, gently squeeze out any water. Add the sour kraut and sausage to the egg noodles. Place on low heat and mix together. Stir often and heat through.
Serve and enjoy.