French Onion Soup Recipe Gets A Modern Update

People have been enjoying soup made from onions since ancient times, but the practice of caramelizing the onions before simmering them into a broth appears to be a 17th-century Parisian innovation (via Food Timeline). "Cut your onions into very thin slices, fry them in butter, and after they are fried put them into a pot of water," a French recipe for "potage of onion" from 1653 instructs.  The practice of cooking the caramelized onions in beef broth, rather than water, appears to have been introduced in 18th-century France, which may be the point in time when French onion soup began to make the transition from everyday "peasant" fare to "special-occasion" dish, which is how it's been regarded since the 1960s when French cuisine became an American obsession (via Literary Hub). 

That also appears to be where some confusion has arisen. As impressive a showing as French onion soup makes on any table, it is not difficult or particularly time-consuming to make –  provided you use an Instant Pot, which has redefined what constitutes a one-pot meal, as this recipe for French onion soup, developed by registered dietitian and food blogger, Kristen Carli, demonstrates. "I love using my Instant Pot for everything," Carli told Mashed, and this dish, inspired by a wonderful French onion soup she enjoys at a local French Bistro, struck Carli as a perfect candidate for recreating using her Instant Pot. 

"The classic way to make French onion soup" is using yellow onions, recipe developer and registered dietitian Kristen Carli told Mashed, which is why Carli's recipe for Instant Pot French onion soup calls for yellow onions. However, if you're curious about exploring the subtle difference in flavor profile between white onions and yellow onions, Carli wholeheartedly recommends going with white onions. Carli also endorses using red onions, leeks, or a combination of various onions, although it may be worth noting that once you start swapping out yellow onions, you may be on a slippery slope toward the making of English onion soup, rather than French (if that matters to you). 

In addition to the onions (you'll need eight, or about 4 pounds worth), you'll also need 2 tablespoons of unsalted butter, a half teaspoon of dried thyme, a bay leaf, 1 teaspoon of salt, a half teaspoon of pepper, and 6 cups of beef broth — for the soup, itself. You might also decide to add in a few tablespoons of cognac along with the beef broth. For the gratinée topping, you'll need a loaf of French bread, 6 slices of Gruyere cheese, and 6 more pinches of thyme.

Even the National Onion Association admits that "cutting onions could be one of the most dreaded jobs in the kitchen." However, you can't make French onion soup without slicing some onions, and at least in the case of this recipe for Instant Pot French onion soup, you won't have to cut them particularly thin. "Because the onions cook down significantly, the exact size does not matter so much," Kristen Carli told Mashed, and you'll be fine if you aim for anything less than half-inch thick slices, and they don't have to be uniform in size or appearance. This method for slicing onions will work perfectly as long as you stop before the "dicing" step.

One of the reasons that French onion soup is so wonderfully aromatic is that it starts with caramelizing the onions, which means cooking them slowly but at a high enough temperature that their sugar content breaks down, releasing a sweet, vaguely nutty flavor, which compliments the onion's essential pungent and mildly bitter notes. Caramelizing onions is a cinch when you have an Instant Pot, since it does the temperature-setting for you. Simply add your butter and onions, and set to "Sauté" mode for 15 minutes. However, you'll want to stir your onions occasionally throughout this process. This will ensure they're both cooking evenly and help them become "tender and translucent" without burning. 

"Be sure to cook down the onions enough," Carli points out. "You will want to make sure they drastically reduce in size and become caramelized." If 15 minutes isn't enough, add on a few more minutes, continuing to stir and watch to make sure you stop the process before the onions start significantly browning.

Once your onions have reached caramelized perfection, it's time to add your thyme (the 1/2 teaspoon), bay leaf, salt, pepper, and beef broth. Be sure to leave the bay leaf whole (i.e., don't crumble it!), since you'll be removing it before serving your Instant pot French onion soup. Although many French onion soup recipes benefit from a splash of spirits, including Julia Child's iconic recipe (via Julia Child's Recipes), Carli developed this recipe to work without the need for that. However, if you'd like to add a few tablespoons of cognac, sherry, or even red wine, Carli thinks that would be delicious too. 

Close and seal your Instant Pot, and set it to "Pressure Cook" mode for five minutes. When the timer is up, release the valve — and make sure to get out of the way because that steam will be hot.

Technically speaking, the golden-brown, sweet and savory soup that is sitting in your Instant Pot right about now would be perfectly delicious as is. However, the fact remains that no French onion soup would be truly complete without its toasty, melted-cheese-topped crouton. To make quick and easy work of what might otherwise be an involved and messy process, you'll want to set up your "gratinée assembly line" as follows: 

Take out six oven-safe bowls (or "ramekins," as Carli refers to them), and set them on baking sheets. Cut six half-inch slices from your French bread. Take your sliced Gruyere cheese out of the refrigerator, and have thyme at the ready. Move an oven rack close to your broiler's heat source, set the broiler to its highest setting, and grab a soup ladle.

When your broiler has finished preheating, it's time to put that "gratinée assembly line" into motion. After removing the bay leaf from the soup, ladle the soup evenly into your six ramekins, making sure to include a generous portion of caramelized onions in each. Top all the ramekins with a slice of French bread. Then top all with a slice of Gruyere cheese. Sprinkle each with a pinch of thyme. Carefully move your baking sheets to the rack you placed near your broiler's heat source, close the door, and allow to broil for two minutes, but watching carefully to prevent burning. 

Using a potholder, carefully remove the baking pans from the oven. Still using a potholder, place each ramekin on a plate, and serve while still hot.