I tinkered with this recipe for quite a while; it’s now the only one I’ll ever use. Cubing the bread instead of laying a whole slice on top of the soup makes it much easier to eat, as well as giving the top an appealing craggy texture. Don’t skimp on the onions; when you are chopping, three pounds seems like a lot, but the long, slow cooking process greatly reduces their volume. The brandy really makes a difference; buy one of those tiny bottles if you don’t have any on hand. I usually make the soup a day ahead; it seems to taste even better that way! If you don’t have French onion soup bowls (see photo below), check your local thrift shop or keep an eye out at garage sales.
2 tablespoons butter
3 pounds onions, sliced
2 tablespoons flour
1 cup chicken broth
3 cups beef broth
2 tablespoons dry white wine
2 tablespoons brandy
1 teaspoon Dijon mustard
salt and pepper, to taste
4 – 5 thick slices of French bread, in 1 inch cubes
½ cup grated mozzarella
½ cup grated Emmentaler (Swiss) Cheese
- Arrange bread cubes on a baking sheet and lightly toast in a 250F oven until just starting to get crunchy.
- Set aside and let cool; store in a bag if not serving soup till the next day.
- In a large, heavy saucepan, melt butter over medium heat.
- Add onions and pinch of salt.
- Cover pan and sauté until onions are very soft, stirring occasionally, about 20 minutes. To caramelize the onions, remove the pan’s lid and increase heat to medium-high; cook, stirring often, onions are taking on a golden brown hue (10 – 15 minutes).
- Reduce heat to medium again; add flour and continue to cook, stirring, for 2 minutes.
- Add chicken and beef broths, wine, brandy and mustard.
- Increase heat until soup comes to a boil, stirring frequently.
- Once boiling, reduce heat to medium-low, replace the lid on the pan and simmer for about 30 minutes. Season to taste with salt and pepper.
- Note that you can prepare to this stage one day ahead; transfer soup to airtight containers and refrigerate. At serving time, reheat the soup in a pot before continuing.
- Arrange oven rack to second-highest position and preheat broiler.
- Ladle hot soup into four deep broiler proof bowls placed on a sturdy baking sheet (you can use 2 cup ramekins if you don’t have French onion soup dishes).
- Top soup with bread cubes and combined cheeses, distributing both evenly among the dishes.
- Broil just until cheese is melted and starting to turn brown.