Green Pea Soup

Ingredients (9)

• 1 tablespoon unsalted butter
• 1 medium leek, root trimmed, halved lengthwise, and thinly sliced (white and green parts only)
• 2 teaspoons kosher salt, plus more as needed
• 2 1/2 cups homemade vegetable broth (see recipe intro) or 1 cup low-sodium store-bought vegetable broth mixed with 1 1/2 cups water
• 1/8 teaspoon freshly ground black pepper, plus more as needed
• 3 cups shelled fresh peas (from about 2 1/2 pounds of peas in their pods) or 1 (16-ounce) package frozen peas, thawed
• 1/4 cup loosely packed fresh mint leaves
• 1 teaspoon freshly squeezed lemon juice, plus more as needed
• Crème fraîche, for serving (optional)