It’s nearly March in Chicago and spring can’t come soon enough. One way to ward off the last remains of winter is with hearty, filling, French Onion Soup. It is a French phenomenon: sweet and savory, gooey and cheesy. Now it can be your phenomenon, Fellow FoodBeest.
A legendary soup that seemed to have developed in Lyon, there are many variations of French onion soup. One thing for sure, Fellow FoodBeest, this soup needs a lot of onions cooked slowly, sloowly, slooowly to bring out all their sweetness. But I think the best part is the lots of ooey-gooey, nutty, stretchy Gruyère cheese melted on top of the French croutons that you will float in the soup.
This recipe, adapted from Cooks Illustrated uses a novel approach to the onions by cooking them for 3 hours in the oven, rather than on the stovetop.
I experimented with it a lot because I just wasn’t sure what I wanted. I tried it on different days. I tried different kinds cheeses (mozzarella, provolone, parmesan and Gruyère) I tried the cheese sliced and grated. I tried different quantities of different cheeses. I ate a lot of French onion soup. At one point, I think I smelled like French onion soup. Very French. Not French like Channel No. 5, but very French nonetheless. And all in your interest of course, Fellow FoodBeest.
Here’s what I learned.
1) Like most soups, this one is best if you make it a day in advance. Two days is even better. It continues to mellow and the flavors come together more like a well-practiced symphony than just a bunch of great musicians who get together to jam.
2) Use Gruyère cheese and plenty of it. Not what we Americans mostly call Swiss cheese, also known as Emmenthal. Emmenthal is the yellow cheese with holes in it (although not all Emmenthal has holes). I happened to be lucky enough to find a good aged Gruyere that was pre-sliced, but it’s not that big a deal if you have to slice it yourself.
What It Takes to Make French Onion Soup
3 tablespoons unsalted butter , cut into 3 pieces
6 large sweet or yellow onions (about 4 pounds), halved and cut pole to pole into ¼-inch-thick slices
[I used a combination of sweet onions and yellow onions]
2 C water, plus ¼ C extra for deglazing
½ C dry sherry
[although some people swear by red wine here and others like cognac]
2 C chicken broth
[I used chicken broth that I routinely make from the leftovers of a rotisserie chicken but the stuff in the can or the box works fine]
4 C beef broth
6 sprigs fresh thyme, tied with kitchen twine
1 bay leaf
Salt and freshly ground black pepper
1 small baguette , cut into 1/2-inch slices
2-3 ounces Gruyère cheese for each ramekin
What You Do To Make French Onion Soup
Adjust the oven rack to the lower-middle position and heat the oven to 400 degrees.
Generously spray the inside of a large (at least 7-quart) heavy-bottomed Dutch oven with nonstick cooking spray. Place the butter in the pot and add the onions and 1 teaspoon salt.
Cook, covered, for 1 hour. Remove the pot from the oven. The onions will “sweat” during the process and when you peek at them an hour later, they will be moist and slightly reduced in volume. Stir the onions, scraping the bottom and sides of the pot. Return the pot to the oven, this time with the lid slightly ajar.
After another hour, take the Dutch oven out and stir the onions, scraping the bottom and side of the pot. Put it back in the oven for another 30-45 minutes.
You will be left with about half of the volume of onions that you started with and they will be very soft and golden brown.
Carefully remove pot from the oven and place it on a burner on the stove over medium-low heat. Using oven mitts to handle the pot (it will be very hot), cook onions, stirring them frequently and scraping the bottom and sides of the pot until the liquid evaporates and the onions turn mahogany brown, 15 to 20 minutes. If the onions are browning too quickly, reduce the heat even further. Be very careful here. It is very, very easy to burn the onions and leave your soup tasting charred instead of sweet and succulent.
Stir in ¼ cup water, scraping the pot bottom to loosen any bits that have attached to the bottom of the Dutch oven. Stir in the sherry and cook, stirring frequently, until the sherry evaporates, about 5 minutes.
Stir in both broths, water, thyme, bay leaf, and ½ teaspoon salt, scraping up any final bits of browned crust on bottom and sides of pot.
Increase heat to high and bring to simmer. Reduce the heat to low, cover, and simmer for 30 minutes. Remove and discard herbs. Taste, then season with salt and pepper as needed.
While the soup simmers, arrange the baguette slices in single layer on baking sheet and bake in a 400-degree oven until the bread is dry, crisp, and golden at edges, about 10 minutes. Set aside.
Adjust oven rack 6 inches from broiler element and heat broiler. Set individual broiler-safe ramekins or crocks on the baking sheet and fill each with about 2/3 of the way to the top with the soup. Top each bowl with 1 or 2 baguette slices (do not overlap bread) and layer with at least two slices (one ounce each) of Gruyère. Three is better. Four if you dare.
Broil until cheese is melted and bubbly around edges, 2-3 minutes. Let cool briefly before serving.
Leftovers (if you have any) freeze really well.