Prep time: 1 hour 30 minutes
Adapted from House and Garden UK
- 2 ounces unsalted butter
- 1 tablespoon olive oil
- 21 ounces sweet onions, peeled, halved and sliced thinly
- 300 grams banana shallots, peeled, halved and sliced thinly
- 2 leeks, trimmed and sliced finely (white and green parts only)
- salt and fresh pepper to taste
- 1 teaspoon sugar
- 4 garlic cloves, peeled and thinly sliced
- 2 tablespoons plain flour
- 8 ounces dry white wine
- 1 quart and 8 ounces of beef stock
- 4 slices French bread
- 4 ounces Manchego cheese, finely grated
- 1 teaspoon thyme leaves
- Melt the butter and oil in a heavy saucepan. Add onions, shallots and leeks, with a pinch of salt, and cook gently for 30 minutes, stirring occasionally.
- Vegetables should be soft and pale.
- Sprinkle sugar into pot and cook uncovered for another 20 minutes, until liquid has evaporated and onions and leeks caramelize to golden brown.
Add flour, stirring it into the mixture.
- Increase heat to medium and add the wine and beef stock.
- Bring to a boil, then cover and simmer for 20 more minutes.
- Correct seasoning.
- Slice and toast bread on both sides.
- Divide the soup between heatproof bowls and put a slice of bread on top of each.
- Top with grated cheese and half of the thyme and place under broiler for a few minutes until cheese is melted and bubbly.
- Scatter rest of thyme and serve.