1/4 cup butter
3 large yellow onions, sliced
1 cup dry white cooking wine
3 can (approx. 14-oz each) beef (or chicken) broth
1/2 tsp thyme
1/2 tsp salt
1 tsp Worcestershire sauce
4 thick slicesbFrench bread, toasted
4 oz shredded Swiss cheese
Fresh thyme or parsley for garnish, if desired
In a large skillet, over high heat, melt the butter; add the onions and cook, stirring, for 15 minutes or until the onions are lightly browned. Stir in the wine.
In a slow cooker or crockpot, combine the onion mixture from the skillet with the broth, thyme, salt, and Worcestershire sauce. Place lid on cooker and cook for 4 to 5 hours on low setting.
To serve, ladle the soup into individual serving bowls, top with one of the toasted bread slices and the cheese. Garnish with the thyme or parsley, if desired.