French Onion Soup is such a classic. It’s what you eat on your first trip to France, and even if you eat it at the restaurant down the street at home all the time, it is still special and memorable. Soupe à L’oignon Gratinée. The rich onion-y broth, the crispy bread soaking up the flavor, the gooey melted cheese dripping off your spoon. It’s delicious to savor and fun to eat.
There are a million recipes, methods and family secrets for French Onion Soup, and I in no way would presume to replace your time-honored tradition. But this is how I make it, rich with layers of flavor and every French twist I could come up with. I have studied many recipes, eaten more bowls than I care to remember and worked for years to perfect it – for me. It may not pass muster with fine French chefs or traditional French grandmothers, but it is deep and rich and lovely and infinitely comforting. It retains its onion essence, with the complexity of beef broth and the crisp, sweet apple cider that pairs with the onions beautifully. A touch of Calvados, the French apple brandy, a splash of vermouth and a healthy dash of Dijon mustard meld to create a subtly, but decidedly Gallic flavor.
Now, as much as I love a good onion soup, bad onion soup is often just salty broth with stringy onions in a mass at the bottom covered with rubbery cheese. To avoid that onion lump, I prefer to puree the soup base to get an onion flavor throughout the soup. You can skip this if you want, but I really think you’ll be impressed with the results.
There is a French bistro here that serves a lovely French Onion Soup, topped as it should be with molten bubbling cheese, the bowl having been placed under the restaurant broiler – known as a salamander – to melt and brown. I ordered it on a date several years ago, and it arrived so unbelievably hot, that I seared the inside of my mouth when took my very lady-like first spoonful. It is a testament to my fortitude and fine upbringing that I did not scream and spit the soup on my date. Sitting through the rest of the meal, trying to delicately chew my salad, was agony, and the soup was not cool enough to finish until dessert came. This has altered my usual preparation. I often toast the bread slices lightly on one side, turn them over, sprinkle with grated cheese and melt these cheesy toasts under the broiler, then float them on the soup. I give the traditional directions below, but you might consider the less fraught method And I chose fontina as the best melty cheese with a flavor that doesn’t overpower the soup.
Almost –Too-French Onion Soup
Using yellow and red onions adds an extra layer of flavor, but all yellow onions could be used. I prepare the onions by using the grating blade in the food processor. Placing the paper on the onions helps them to soften and brown and retain their rich flavor. Brandy can be used in place of the Calvados, but the Calvados adds a special touch.
5 Tablespoons butter
3 Tablespoons olive oil
2 cups diced red onion
2 cups diced yellow onion
2 teaspoons salt
1 teaspoon black pepper
1 Tablespoon Calvados
2 Tablespoons white vermouth
4 Tablespoons light brown sugar
1 teaspoon dried thyme
1 teaspoon dried oregano
1 1/2 cups apple cider
2 Tablespoons Dijon mustard
7 cups low-sodium beef broth
sliced white bread or baguette
1 cup grated fontina cheese
Cut a piece of waxed paper to fit inside your Dutch oven and press it down in the pan to create the shape of a tight-fitting lid and set aside. You’ll press this over the onions to help them caramelize. By the way, this is called a cartouche.
Melt butter with olive oil in a large stockpot or Dutch oven over medium high heat. When the butter has just melted, add the onions and sauté until translucent and just starting to brown. Add the Calvados and vermouth and stir to deglaze the pan. Add the brown sugar, thyme, oregano, salt and pepper and 1/2 cup cider. Press the prepared round of waxed directly over the onions. Reduce the heat to medium low and cook until the onions are soft and sweet and brown, about 20 minutes.
Remove the paper round, stir in mustard and cook 5 more minutes. Add the remaining one cup cider and 3 cups beef broth. Bring to a simmer. Puree with an immersion blender, or puree in a blender in batches (be very careful as hot liquids will pop the top off the blender, so hold it tight with a tea towel). Return to pan. Add the remaining broth and bring to a low boil. Simmer for ten minutes and check for seasoning, adding salt and pepper as needed. Remove from heat and dish into oven proof bowls placed on a baking sheet. Top with bread and grated cheese. Place under the broiler in the oven until the cheese melts and begins to brown. Be careful when serving as the bowls will be very hot.
The soup, without the bread and cheese, will keep for 1 to 2 days covered in the refrigerator. Slowly reheat over medium heat. The soup also freezes beautifully.