A both delicate and deeply satisfying soup

Serves 4 to 6

Few soups capture the essence of spring as purely as this one. Asparagus and leeks are natural partners, the grassy brightness of asparagus lifting the sweet, mellow depth of slow-softened leeks into something that tastes both delicate and deeply satisfying. A touch of white wine adds acidity, crème fraîche brings a subtle tang, and a finish of tarragon ties the whole bowl together with an anise-like whisper that is unmistakably French in spirit but at home on any table. Serve warm with a crusty baguette and a glass of unoaked Chardonnay or Sauvignon Blanc, or chilled on a warm evening as an elegant first course.

Ingredients

For the soup

• 2 pounds fresh asparagus, woody ends snapped off, tips reserved separately, stalks cut into 1-inch pieces
• 3 large leeks, white and light green parts only, halved lengthwise, cleaned thoroughly, and thinly sliced
• 3 tablespoons unsalted butter
• 2 tablespoons extra virgin olive oil
• 4 cloves garlic, minced
• 1/2 cup dry white wine
• 4 cups good quality vegetable or chicken broth, warmed
• 1 medium Yukon Gold potato, peeled and diced small (adds body without heaviness)
• 1/2 cup crème fraîche, plus more for serving
• 1 teaspoon fresh lemon juice
• 1 teaspoon fresh tarragon leaves, plus more for garnish (or 1/4 teaspoon dried)
• Kosher salt and freshly ground white pepper to taste

For the garnish

• Reserved asparagus tips, blanched
• A swirl of crème fraîche
• Fresh tarragon leaves
• Flaky sea salt
• Good drizzle of extra virgin olive oil

Directions

1. Bring a small pot of salted water to a boil. Blanch the reserved asparagus tips for 2 minutes, then transfer immediately to an ice bath to preserve their bright green color. Drain and set aside for garnish.
2. In a large heavy pot or Dutch oven, melt butter with olive oil over medium-low heat. Add the leeks and a generous pinch of salt. Cook slowly, stirring occasionally, until completely softened and silky but not browned, about 12 to 15 minutes. Low and slow is the key here.
3. Add the garlic and cook for 1 to 2 minutes until fragrant.
4. Pour in the white wine and raise heat to medium. Stir and let the wine reduce by half, about 2 minutes.
5. Add the diced potato and asparagus stalk pieces. Stir to coat everything in the leek base.
6. Pour in the warmed broth. Bring to a gentle simmer and cook uncovered until the potato and asparagus are completely tender, about 15 to 18 minutes.
7. Remove from heat and let cool slightly. Add the crème fraîche and tarragon to the pot.
8. Using an immersion blender, blend the soup until completely smooth and velvety. Alternatively, blend in batches in a countertop blender, filling it no more than halfway and venting the lid carefully.
9. Return the blended soup to low heat. Stir in lemon juice and taste carefully. Adjust salt and white pepper as needed.
10. If the soup is thicker than you prefer, thin it with a splash of warm broth until it reaches your desired consistency.
11. Ladle into warmed bowls. Garnish each serving with blanched asparagus tips, a swirl of crème fraîche, fresh tarragon leaves, a pinch of flaky sea salt, and a drizzle of olive oil.

Tips and variations

• White pepper instead of black keeps the soup visually clean and pure green without dark flecks
• The Yukon Gold potato is the secret to a luxuriously thick, creamy texture without needing heavy cream
• Do not skip the ice bath for the asparagus tips, it is what keeps the garnish a vivid, beautiful green
• For a fully vegan version, substitute olive oil for butter, coconut crème fraîche or cashew cream for the crème fraîche, and use vegetable broth
• For a chilled version, blend the soup, cool completely, then refrigerate for at least 2 hours and serve cold with the garnishes, it is stunning in summer
• A small handful of fresh spinach added just before blending deepens the green color beautifully without affecting the flavor
• Leeks trap a surprising amount of grit between their layers, halve them lengthwise and rinse thoroughly under cold running water before slicing