Slice Onions
1
Slice onions into ¼-inch slices. Add to a soup pot with olive oil. Begin to sauté over medium heat, stirring occasionally.
Add Butter
2
When the onions begin to get a little color (after about 30 minutes) add the butter. Continue to sauté, stirring occasionally.
Deglaze, if needed.
3
If the bottom of the pot begins to brown faster than the onions, add a couple tablespoons of water to dissolve the browned bits off the bottom as the onions continue to cook.
Add flour
4
When the onions are fully caramelized (deep brown color, jammy texture), add the flour. Continue to cook and stir for about two minutes more.
Add broth
5
Add beef broth and stir to dissolve the browned bits off the bottom of the pot.
Add herbs
6
Also add dried thyme, bay leaf, black pepper, and Worcestershire sauce. Simmer for 30 minutes.
Toast bread
7
Toast slices of bread under the broiler, just until they begin to turn a little golden brown.
Top with bread and cheese
9
Top each bowl with a piece of toasted bread and some shredded Swiss or Gruyere.
Broil again
10
Place the bowls back under the broiler for a few minutes more, or until the cheese is melted and bubbly.