Caramelized Onion–Tomato Soup

Ashley Christensen

Poole’s Diner, Raleigh, NC

"This recipe combines two of the most comforting soups in existence—tomato soup and French onion soup—into one powerhouse of a bowl. The key to nailing this dish is patience: each step, from slowly caramelizing the onions to reducing the tarragon stock, takes time. You’ll be rewarded on the other side with a rich and complex flavor with the heft of beef stock, even though the soup is entirely vegetarian. The soup is great on its own, but the addition of melty Jarlsberg cheese and toasted baguette makes it worthy of a special occasion (or a proper rainy day)." —Ashley Christensen


Serves 6



  • 1/2 cup olive oil
  • 6 cloves garlic, crushed
  • Two 28-ounce cans diced tomatoes
  • Sea salt
  • 2 tablespoons neutral vegetable oil
  • 2 pounds yellow onions, halved and thinly sliced (about 6 cups)
  • 4 cups dry white wine
  • 1/4 cup white wine vinegar
  • 6 to 7 whole sprigs tarragon, leaves intact
  • 1 tablespoon whole-grain mustard


  • 1 tablespoon neutral vegetable oil
  • 1/2 baguette, sliced into 1/4-inch-thick slices
  • 1 tablespoon unsalted butter
  • 1/2 cup grated Jarlsberg (any nutty, melty cheese, such as Gruyère, would work well here)


In a large Dutch oven, combine the olive oil and garlic. Place over medium heat and cook, stirring occasionally, until the garlic is toasted, about 2 minutes. Add the tomatoes and 2 teaspoons sea salt and increase the heat to bring to a boil. Reduce to a simmer. Cook for 45 minutes; the tomatoes and garlic will be falling apart and the flavors will be cohesive.

Meanwhile, in a high-sided sauté pan, heat the vegetable oil over medium heat. Add the onions and 2 teaspoons salt. Turn the heat to high, stirring frequently. Once the pan is hot (about 1 minute), reduce the heat to medium and cover; cook, covered, for 20 minutes. When you remove the lid, lots of moisture will escape, and the onions will have begun to caramelize. Cook, stirring, until the onions are thick and deep brown. Transfer the onions to a bowl and return the pan to high heat.

Add the wine, vinegar, and tarragon. Cook until the liquid has reduced down to become thick and syrupy. Add 6 cups water and bring to a boil, then remove from heat.

Strain the tarragon infusion into the stewed tomato mixture, discarding the solids. Stir in the caramelized onions, mustard, and 2 teaspoons salt. Bring the soup to a boil, then reduce to a simmer and let simmer for 20 minutes.

While the soup is simmering, make the croutons. Line a plate with paper towels. In a large skillet over high heat, heat the oil. When it shimmers, add the baguette slices in an even layer; when they begin to turn golden on the bottom side, add the butter, turn down the heat to medium, and stir to coat. Fry the bread for 3 to 4 minutes on one side, until it is a dark golden brown. Transfer to the paper towel-lined plate.

Stack 3 croutons in the center of each of 6 oven-proof soup bowls, placing a small pinch of cheese between each layer. Ladle the soup around the stacks of bread to fill the bowls. Sprinkle a last pinch of cheese in the center of each bowl. Place the bowls under the broiler and cook for 2 to 3 minutes, until the cheese is melted and bubbling. Serve.