Melt 2 tbsp of butter in a large saucepan. Add the onion and caramelized (about 20 min). NOTE: Be sure not to burn the edges, if they are beginning to burn you can add a small amount of water to the pan.
Add the minced garlic and cook until fragrant (about 2 minutes).
Deglazed the pan with white wine. Pour the mixture into a large pot and add the beef broth. Bring to a boil, then reduce heat.
Stir in the minced sage and season to taste with salt and pepper.
Serve topped with cheese and a side of toasted bread to dip.
Notes
Any other bread can be substituted for the sourdough, croutons are great as well.