In a Dutch oven or large soup pot, heat the oil & butter over medium heat. When the butter has melted, add all of the onions. Cook the onions, stirring occasionally, over medium/medium-low for about 25 minutes until they are caramelized {golden brown}.
Add the garlic and stir for 30 seconds.
Stir in the red wine and broth. Scrape up any bits of onion that are stuck to the pot.
Add in the Worcestershire sauce, salt, dried thyme, and bay leaf. Stir well. Bring to a boil, and reduce heat to a simmer.
Simmer for 25-35 minutes, stirring occasionally.
Meanwhile, toast bread on both sides. Sprinkle with cheese and melt cheese over toast. Cut into cubes. Set aside.
Stir fresh thyme into soup. Serve soup with cheese toasts.
Notes
*To make this vegan, use avocado or olive oil in place of the butter and omit the Worcestershire sauce. Skip the cheese or use a non-dairy cheese*If you do not need it to be meatless, use 2 cups low-sodium chicken broth + 2 cups low-sodium beef broth in place of the 4 cups vegetable broth