French onion soup is a luxuriously delicate soup that isn’t usually the first soup you think of when the weather is cold and you want something hearty and stick-to-your-ribs… until you top it with crusty bread and a thick cap of bubbly, golden Gruyere.
Baby, that’ll stick to my ribs. And heart. And with all that Gruyere, my face.
A fantastic bowl of French onion soup is hard to come by, but when you find it, you hold on to it. A richly flavored broth packed with slllllowwwwwly caramelized onions, a thick slice of garlicky baguette that soaks up the broth as it sits, and (can’t say it too many times!) there’s that cap of bubbly, golden Gruyere. Preferably oozing down the side of the bowl. Breaking through the cheese cap should bring the same euphoria as tap-tap-tapping the crust of a creme brûlée. GAH, such joy!!
This French onion soup recipe is the one I have used for years, and it’s my favorite for two reasons: it’s soooooo good, and it shortcuts the active caramelization time by using the oven. In lazy cook (aka my) terms: no slaving away stirring those onions till your hair turns gray!!
Wait. You read the recipe. I am claiming ‘no slaving’ yet there are still 40 long minutes of caramelizing?? Aren’t these antipodean concepts?? And did I just use the word ‘antipodean??’
Here’s the rub that no one tells you about caramelizing onions: reeeeeeeally caramelizing onions takes forever. All those recipes out there that call for caramelizing the onions for 25 minutes are totally lying. In 25 minutes, you will have slightly golden, softened onions that would be perfect on a burger but not even sniffing the arena of how deeply, deeply browned they need to be for a French onion soup. Caramelizing the 4 pounds of onions in this recipe to perfection would take at least 2 hours of stirring over low heat, maybe more. Pro: you’ll have nice arms; con: you’re stirring for two hours. That’s one whole Downton Abbey premiere.
This recipe? You pop the onion-packed pot in the oven for 2 1/2 hours, stirring only twice, and voila! You have perfectly softened onions that start to caramelize instantly as you start stirring them on the stove. About 40 minutes later, you’re looking at deep, dark, prime caramelized onion real estate. That is the stuff worthy of French onion soup.
Once you have those perfectly caramelized onions, the soup just has a little simmering to do before you top it with that bread and that mountain of Gruyere. Then you broil it and watch it ooooooooze down the sides of the bowl, and right to your heart.
(Photo above credited to the very talented Brittany Payne of Brittany Payne Photography. She made this soup the same day I did, so I begged her to take a photo because my snaps, while demonstrating much cheese ooze, were dreadful. She’s a professional photographer and, if I may say, a damn fine cook. Thanks, Brittany!!)
- 3 T butter, cut into 3 pieces
- 6 large Spanish onions, about 4 pounds, halved and cut into ¼″-thick slices
- Kosher salt
- 2 c water, plus extra for deglazing
- ½ c dry sherry
- 4 c low-sodium chicken broth
- 2 c low-sodium beef broth (homemade or Pacific brand recommended)
- 6 sprigs fresh thyme, tied with kitchen twine
- 1 bay leaf
- Freshly ground black pepper
- Cheese Croutons:
- 1 small baguette, cut on bias into ½″-thick slices
- 8 oz Gruyere, shredded (about 2½ cups)
- Adjust oven rack to lower-middle position and heat oven to 400 degrees F. Generously spray inside of heavy-bottomed large (at least 7-quart) Dutch oven with non-stick cooking spray. Place butter in pot and add onions and 1 tsp salt. Cook, covered, 1 hour (onions will be moist and slightly reduced in volume).
- Return pot to oven with lid slightly ajar and continue to cook until onions are very soft and golden brown, 1½-1¾ hours longer, stirring onions and scraping bottom and sides of pot after 1 hour.
- Carefully remove pot from oven and place over medium-high heat. Using oven mitts to handle pot, cook onions, stirring frequently and scraping bottom and sides of pot, until liquid evaporates and onions brown, about 15 minutes, reducing heat to medium if they are browning too quickly. Continue to cook, stirring frequently, until pot bottom is coated with a dark crust, 6-8 minutes, adjusting heat as necessary. (Scrape any fond that collects on spoon back into onions). Stir in ¼ c water, scraping pot bottom to loosen crust, and cook until water evaporates and pot bottom has formed another dark crust, 6-8 minutes.
- Repeat process of deglazing 2 or 3 more times (the more times, the deeper the flavor!), until onions are very dark brown. Stir in sherry and cook, stirring frequently, until sherry evaporates, about 5 minutes.
- Stir in broths, 2 c water, thyme, bay leaf, and ½ tsp salt, scraping up any final bits of browned crust on bottom and sides of pot. Increase heat to high and bring to simmer. Reduce heat to low, cover, and simmer 30 minutes. Remove and discard herbs, then season with salt and pepper to taste.
- Make the croutons: White soup simmers, arrange baguette slices in single layer on baking sheet and bake in 400-degree F oven until 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 crocks on baking sheet and fill each with about 1¾ cups soup. Top each bowl with 1 or 2 baguette slices (do not overlap slices) and sprinkle evenly with Gruyere. Broil until cheese is melted and bubbly around edges, 3 to 5 minutes. Let cool 5 minutes before serving.