Serves 4 to 6 • Gluten-Free
Why This Recipe Works: We wanted a deceptively delicious, silky-smooth soup that delivered a big dose of healthy greens. It would be packed with all the essential nutrients of hearty greens and would boast a deep, complex flavor brightened with a garnish of lemon and herb cream. First, we built a flavorful foundation of sweet caramelized onions and earthy sautéed mushrooms. We added broth, water, and lots of leafy greens (we liked a mix of chard, kale, arugula, and parsley), and simmered the greens until tender before blending them until smooth. We were happy with the soup’s depth of flavor, but it was watery and too thin.
Many recipes we found used potatoes as a thickener, but they lent an overwhelmingly earthy flavor. Instead, we tried using Arborio rice. The rice’s high starch content thickened the soup to a velvety, lush consistency without clouding its bright, vegetal flavors. For a vibrant finish, we whisked together heavy cream, sour cream, lemon zest, lemon juice, and tarragon and drizzled it over the top.
1/4 cup heavy cream
3 tablespoons sour cream
2 tablespoons plus 1/2 teaspoon extra-virgin olive oil
1/4 teaspoon finely grated lemon zest plus 1/2 teaspoon juice
1/2 teaspoon minced fresh tarragon
Salt and pepper
1 onion, halved through root end and sliced thin
3/4 teaspoon light brown sugar
3 ounces white mushrooms, trimmed and sliced thin
2 garlic cloves, minced
Pinch cayenne pepper
3 cups water
3 cups vegetable broth
1/3 cup Arborio rice
12 ounces Swiss chard, stemmed and chopped coarse
9 ounces kale, stemmed and chopped coarse
1/4 cup fresh parsley leaves
2 ounces (2 cups) baby arugula
1. Combine cream, sour cream, 1/2 teaspoon oil, lemon zest and juice, tarragon, and 1/4 teaspoon salt in bowl. Cover and refrigerate until ready to serve.
2. Heat remaining 2 tablespoons oil in Dutch oven over medium-high heat. Stir in onion, sugar, and 1 teaspoon salt and cook, stirring occasionally, until onion releases some moisture, about 5 minutes. Reduce heat to low and cook, stirring often and scraping up any browned bits, until onion is deeply browned and slightly sticky, about 30 minutes. (If onion is sizzling or scorching, reduce heat. If onion is not browning after 15 to 20 minutes, increase heat.)
3. Stir in mushrooms and cook until they have released their moisture, about 5 minutes. Stir in garlic and cayenne and cook until fragrant, about 30 seconds. Stir in water, broth, and rice, scraping up any browned bits, and bring to boil. Reduce heat to low, cover, and simmer for 15 minutes.
4. Stir in chard, kale, and parsley, 1 handful at a time, until wilted and submerged in liquid. Return to simmer, cover, and cook until greens are tender, about 10 minutes.
5. Off heat, stir in arugula until wilted. Working in batches, process soup in blender until smooth, about 1 minute. Return pureed soup to clean pot and season with salt and pepper to taste. Drizzle individual portions with lemon-tarragon cream, and serve.
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