- 10 large Vidalia or Spanish onions
- ½ cup (125 ml) butter
- 1 tbsp (15 ml) kosher salt
- 2 tbsp (30 ml) all-purpose flour
- ¼ cup (60 ml) sherry vinegar
- 8 cups (2 liter) beef stock
- 1 small French baguette cut a little less than ½ inch (1.25 cm)
- 1 tbsp (15 ml) olive oil
- 8-12 thin slices of Emmentaler cheese-about a 4 inch (10 cm) square
- 2 cups (500 ml) grated gruyere cheese
- 4 bay leaves
- 1 tbsp (15 ml) whole peppercorns
- 1 bunch fresh thyme (about 12 sprigs)
- 6-inch (15 cm) piece of cheese cloth with butcher string for a tie
- Peel onions and remove the tops and core.
- Cut the onions with the grain ¼ inch (.31cm) slices. You should have 7 liters (7.3 quarts) of onions.
- Place butter in a large soup pot set over low heat. Allow to melt.
- Add the onions and salt. (Salt aids in breaking down the cellular structure of the onion.)
- Cook until completely reduced and caramelized all over. Stirring occasionally. Approximately 2 hours.
- Make the sachet by tying peppercorns, thyme and bay leaves in a cheese cloth to make a pouch.
- Once onions have reduced add flour to the pan to absorb any extra oil and add body to soup.
- Add the sherry vinegar.
- Add the beef stock and the sachet. Simmer 1 hour.
- Season to taste with salt and pepper.
- For the croutons take the slices of bread and drizzle with olive oil.
- Place on a baking tray. Place in a preheated 375F (190C) oven to toast for 5 minutes or until golden brown and crispy on both sides. Flipping the bread over if necessary.
- Place onion soup bowls (ovenproof bowls) on a baking tray.
- Fill the bowls with soup leaving a ½ inch (1.25 cm) deep border.
- Top with croutons 2 per bowl and place 2 slices of cheese on top of the crouton.
- Scatter the grated cheese equally over the soup bowls.
- Place under broiler to caramelize and melt the cheese watching closely.
- Or place in preheated 400F (204°C) oven to melt and caramelize the cheese for 15 minutes.
- Remove from oven.