My dear wife and I enjoyed adapting this recipe from Cook’s Illustrated (free online membership required). I know it looks a little putzy and time-consuming (that’s Cook’s Illustrated for you), but the soup is exceptional, and by caramelizing the onions in the oven you really cut down the hands-on time. To make it even easier, we split this into a 2-night cook; preparing the onions the first night while we made dinner, and then finishing the soup in about an hour on the stove top the next night.
It’s been so cold, dark, and rainy around here this week that this soup really hit the spot – rich and filling with a clean onion flavor. It’s so good that the only change I would make (other than maybe trying in on the Big Green Egg ;)) would be to caramelize double the amount of onions and freeze half of them off for a quick meal later.
3 tablespoons butter
6 large yellow onions (about 4 pounds)
2 – 3 cups water
1/2 cup dry sherry or red wine
4 cups chicken broth (we used Pacific Natural, which is gluten free)
2 cups beef broth (Pacific Natural)
1 teaspoon dried thyme
1 bay leaf
Ground black pepper
1 small baguette , cut into 1/2-inch slices and lightly toasted (we used Pamela’s Gluten-Free Bread Mix)
8 ounces shredded raclette or swiss cheese
Heat oven to 400°F and adjust the rack to the lower-middle position.
Halve the onions and cut pole to pole into 1/4-inch-thick slices. Try to stick with yellow onions as this dish needs their lower sugar and stronger, more complex flavor.
Grease a large Dutch oven and add the butter, onions, and salt. Put in the oven and cook, covered, for 1 hour. Remove the pot from the oven and stir the onions, making sure to scape the bottom and sides. Return the pot to the oven with the lid slightly ajar and cook for another hour. Again, remove the pot and give everything a good stir. Return the pot to the oven with the lid slightly ajar continue to cook until the onions are very soft and golden brown (about 30 to 45 minutes).
Remove the pot from the oven. At this point you can let the onions cool in the in the pot and refrigerate for a day or so before continuing with the recipe.
Move the pot to the stove top over medium-high heat. Continue cooking the onions, stirring frequently and scraping bottom and sides of pot, until all the liquid evaporates and the onions brown (about 15 to 20 minutes).
Reduce the heat to medium and continue to cook, stirring frequently, until the pot bottom is coated with a dark crust of fond (about 6 to 8 minutes). Scrape the tasty brown goodness back into onions.
Deglaze the pot with 1/4 cup water, scraping the pot bottom to loosen crust, and cook until the water evaporates and pot bottom has formed yet another dark crust (another 6 to 8 minutes).
Add another 1/4 cut of water and deglaze the pot again, cooking until the water evaporates and pot bottom has formed yet another dark crust (another 6 to 8 minutes).
One more time – deglaze and cook until the water has evaporated and the onions are very dark brown. Stir in the sherry and cook, stirring frequently, until the sherry evaporates (about 5 minutes).
Stir in all the the broths, 2 cups of water, thyme, bay leaf, and 1/2 teaspoon salt, scraping up any remaining 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. Discard the bay leaf and adjust the seasoning with salt and pepper.
Adjust oven rack 6-8 inches from broiler. Set individual broiler-safe bowls or crocks on baking sheet and fill each about 3/4 of the way up with soup. Top each bowl with a few baguette slices and a heavy sprinkle of cheese. Broil until cheese is melted and gotten a little brown ‘n’ bubbly around edges (about 3 to 5 minutes).
Serve immediately with more bread for dipping.