Creamy Broccoli-and-Spinach Soup

Ingredients

• 3 tablespoons unsalted butter
• 2 leeks (about 1 pound), white and light-green parts only, halved lengthwise and thinly sliced crosswise, well washed, and drained (2 cups)
• 3 cloves garlic, smashed and peeled
• 2 teaspoons Dijon mustard
• 3 tablespoons unbleached all-purpose flour
• 4 cups low-sodium chicken or vegetable broth
• 1 small head broccoli (about 12 ounces), stems peeled and cut into ¼-inch coins, head cut into bite-size florets
• Kosher salt and freshly ground pepper
• 5 ounces baby spinach, stems removed (6 packed cups)
• 1/3 cup crème fraîche
• Store bought pretzel nuggets, for serving (optional)

Directions

1. Melt butter in a medium saucepan over medium-high heat. Add leeks and garlic and cook, stirring occasionally, until translucent, about 2 minutes. Stir in mustard, then flour; cook until mixture has a slightly nutty aroma, about 1 minute.
2. Gradually whisk in broth until combined. Add broccoli stems and season with salt and pepper; increase heat to high and bring to a boil, whisking constantly. Add broccoli florets; reduce heat to low and simmer partially covered until broccoli is tender, about 8 minutes. Stir in spinach and cook 1 minute more; remove from heat.
3. Working in batches, purée soup in a blender. Return to pot and reheat over medium-low. Whisk crème fraîche with 1 tablespoon water in a small bowl. Serve soup, drizzled with crème-fraîche mixture and garnished with pretzels.