This soup gets its earthy flavor from a handful of dried porcini mushrooms. To balance the sweetness of the onions, be sure to use a good baguette or sourdough loaf for the toast. Anything too dense or grainy will contribute a sodden texture and a too-sweet overall flavor.
Make Ahead: The soup can be refrigerated in an airtight container up to 4 days in advance. Reheat on the stove top while you toast the bread, just before serving.
Tested size: 4 servings
- 4 1/2 cups water, 2 cups’ worth brought to a boil
- 1/2 ounce dried porcini mushrooms
- 1 1/2 pounds yellow onions
- 3 tablespoons extra-virgin olive oil
- 1 teaspoon sea salt
- 2 cloves garlic, minced
- 2 teaspoons fresh thyme leaves
- 1 cup dry white wine
- 1/4 teaspoon fresh-cracked black pepper, or more as needed
- 8 baguette slices or 4 slices sourdough bread, cut 3/4 inch thick
Pour the 2 cups of boiling water over the mushrooms in a bowl; let soak for about 20 minutes while you cook the onions.
Cut the onions in half, top to bottom. Cut each half crosswise into thin half-moon slices.
Heat a wide, heavy pot or Dutch oven over medium-low heat. Add the oil and swirl to coat, then stir in the onions and 1/2 teaspoon of the salt. Cook for about 30 minutes, stirring a few times, until the onions begin to break down somewhat but are not falling apart. Reduce the heat as needed to keep the onions from sticking or browning excessively; they should remain a pale golden color.
Stir in the garlic and thyme; cook for 5 minutes, then add the wine. Increase the heat to medium-high and cook for 5 minutes or until the wine has reduced by about half.
Place a fine-mesh strainer over the pot; pour in the mushrooms and their soaking liquid, reserving the rehydrated mushrooms. Add the remaining 2 1/2 cups of water; once the liquids in the pot start to bubble at the edges, partially cover and cook for 10 minutes.
Chop the rehydrated mushrooms into small pieces. Add them to the pot along with the pepper and the remaining 1/2 teaspoon of salt. Partially cover and cook for another 20 minutes.
Meanwhile, preheat the oven (or a toaster oven) to 400 degrees.
Toast the bread until crisped and barely golden. Place the slices in the bottom of individual soup bowls. Ladle the soup over the toast; serve hot.
Calories per serving: 350
% Daily Values*
Total Fat: 11g 17%
Saturated Fat: 2g 10%
Cholesterol: 0mg 0%
Sodium: 820mg 34%
Total Carbohydrates: 46g 15%
Dietary Fiber: 5g 20%
*Percent Daily Value based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie needs.
Total Fat: Less than 65g
Saturated Fat: Less than 20g
Cholesterol: Less than 300mg
Sodium: Less than 2,400mg
Total Carbohydrates: 300g
Dietary Fiber: 25g