Preparation Steps
1
Melt butter with olive oil in a large pot over medium heat.
2
Add onions and stir continually until translucent.
3
Add beef broth, marsala and thyme.
4
Simmer for 30 minutes.
5
Add sugar and season with salt and pepper.
6
Be careful not to over salt! Ladle soup into oven-safe bowls and place a handful of croutons in each.
7
Sprinkle parmesan and swiss cheese and layer 2 slices of provolone on top.
8
Place bowls on cookie sheet and broil in the preheated oven until cheese bubbles and browns.