Slice the beef liver into approximately 1/2 inch thick and 2-inch long slices.

Finely slice the onions.

Lightly dust the liver slices with flour.

Heat the butter in a large skillet over medium-high heat.

Add the floured liver and sliced onions to the hot butter.

Stir-fry the liver and onions quickly until the liver is lightly browned on all sides and the onions are translucent. Season with salt and pepper to taste.

Pour the white wine into the skillet, scraping any browned bits from the bottom to deglaze the pan.

Bring the wine to a slow boil, then reduce the heat and add the low-fat whipping cream.

Stir in the sugar and lemon juice.

Heat the sauce through, ensuring it does not boil.

Serve immediately with spaetzle.