This soup is the stuff gooey, cheesy dreams are made of and is perfect for these last drizzly days of winter. It’s one of my most favorite meals.
A few notes – though homemade is best, boxed stock will work – just make sure you use a brand without a lot of sodium. If you want to get extra fancy, add 1/2 cup dry white wine to the onions as you’re pouring in the stock, and stir in 3 tablespoons of cognac or brandy when the soup is simmering.
Finally, don’t fret if you don’t have oven proof crocks; this soup can be served alone (it’s that good) – or place your toast on a lined, greased baking sheet and smother with cheese. Broil for a few moments til the cheese is melted, the serve atop your soup. Serves 6.
1 1/2 pounds yellow onions, thinly sliced
3 tablespoons butter
1 tablespoon olive oil
1 teaspoon sea salt, plus more to taste
3 tablespoons all-purpose flour
2 quarts (8 cups) beef stock
1 teaspoon fresh thyme, chopped
1 teaspoon fresh rosemary, chopped
Freshly ground black pepper
1 1/2 cups grated Gruyere (you can also use Swiss or combination thereof, and a sprinkling of Parmesan never goes amiss).
12 to 16 1-inch thick rounds French bread, toasted until hard
1 tablespoon chives, chopped (optional)
1. Melt the butter and oil in a very large pot over medium-low heat. Add the onions and toss to coat. Cover the pot and reduce the heat to low, then let steep uninterrupted for 15 minutes.
2. After 15 minutes, uncover the pot and raise the heat slightly. Season with salt and cook – stirring frequently – for 30 to 40 minutes until onions are a deep golden brown. Don’t even think about shortchanging this step, no matter how impatient you are.
3. When the onions are golden and caramelized, stir in the flour and the herbs, and cook for 3 minutes. Add in the stock then season to taste with salt and pepper. Let simmer partially covered for half an hour, then bring to boil.
4. While soup is simmering, preheat your oven to broil. Arrange six ovenproof crocks on a foil-lined baking sheet. When the soup boils, ladle into crocks, then float a few croutons on top, so soup is mostly covered. Sprinkle on cheese; how much to use is up to you – I used a 1/4 cup per crock.
5. Place crocks under the broiler for a few minutes til the cheese is melted and the top is lightly brown. Remove from oven and serve immediately, garnished with chives.
Adapted from Mastering the Art of French Cooking