Three Onion Soup

This recipe comes from "Chef Bobo's Good Food Cookbook" I haven't made it yet. I am putting it here so I don't lose it.

• Ready In: 55 mins
• Serves: 4

Ingredients

• 2  tablespoons  vegetable oil
• 2  medium yellow onions, thinly sliced
• 2  medium red onions, thinly sliced
• 6  shallots, halved and thinly sliced
• 1⁄4 cup white wine vinegar
• 2  tablespoons Worcestershire sauce
• 2  tablespoons all-purpose flour
• 5  cups  vegetable stock
• 1  teaspoon dried thyme, crushed
• 2  bay leaves
• 1⁄4 cup dry white wine (optional)
•  salt & pepper

Directions

1. In a pot large enough to hold all of the onions, drizzle the vegetable oil.
2. When the oil is hot, add the yellow and red onions and the shallots.
3. Reduce heat to med.
4. Let the onions cook down, stirring constantly.
5. Continue cooking and stirring until the onions are caramelized (about 30 min).
6. When the onions are a deep shade of brown, add the vinegar and worcestershire sauce.
7. Cook until the liquid has evaporated.
8. Sift the flour over the onions and stir to coat.
9. Cook for 2-3 minutes or until thickened.
10. Transfer to a 3-qt soup pot.
11. Add the vegetable stock, thyme & bay leaves.
12. Simmer over medium heat for 15 minutes, stirring occasionally.
13. If you are using the wine, stir it in and cook 1 minute more.
14. Season to taste with salt & pepper.
15. Remove the bay leaves before serving.