Quick Recipe Version (TL;DR)
Quick Ingredients
- 1.5 lb (680 g) parsnips, peeled and chunked
- 3 medium leeks (white and light green parts), sliced
- 3 tbsp olive oil, divided
- 1 tbsp unsalted butter
- 3 garlic cloves, thinly sliced
- 4 cups (960 ml) low-sodium vegetable or chicken broth
- 1 cup (240 ml) water, plus more as needed
- 3 fresh thyme sprigs, plus extra leaves for garnish
- 1 bay leaf (optional)
- 1/2 cup (120 ml) heavy cream, plus extra for swirling
- 1 tsp kosher salt, plus more to taste
- 1/2 tsp freshly ground black pepper, plus more to taste
- 1–2 tsp fresh lemon juice (optional)
Do This
- 1. Heat oven to 400°F (200°C). Toss parsnips with 2 tbsp olive oil, salt, and pepper. Roast 25–30 minutes until golden and tender.
- 2. Meanwhile, clean leeks well. Slice white and light green parts.
- 3. In a large pot, heat 1 tbsp olive oil and butter over medium. Sauté leeks with a pinch of salt 8–10 minutes until soft. Add garlic; cook 1–2 minutes.
- 4. Add roasted parsnips, broth, water, thyme sprigs, and bay leaf. Simmer 15–20 minutes until everything is very tender.
- 5. Remove thyme stems and bay. Blend soup (immersion blender or in batches) until perfectly smooth.
- 6. Stir in cream. Adjust thickness with more hot water or broth if needed. Season with salt, pepper, and lemon juice to taste.
- 7. Ladle into bowls and finish with a swirl of cream and fresh thyme leaves. Serve hot.
Why You’ll Love This Recipe
- Silky-smooth and luxuriously creamy, with natural sweetness from roasted parsnips.
- Leeks and garlic give a gentle, savory depth without overpowering the delicate flavor.
- Elegant enough for a dinner party, simple enough for a cozy weeknight.
- Make-ahead friendly and perfect for freezing, so you can enjoy it anytime.
Grocery List
- Produce: Parsnips, leeks, garlic, fresh thyme, lemon (optional)
- Dairy: Unsalted butter, heavy cream
- Pantry: Olive oil, low-sodium vegetable or chicken broth, bay leaf, kosher salt, black pepper
Full Ingredients
For the Soup
- 1.5 lb (680 g) parsnips, peeled and cut into 1-inch chunks
- 3 tbsp olive oil, divided (2 tbsp for roasting parsnips, 1 tbsp for sautéing leeks)
- 3 medium leeks, white and light green parts only, halved lengthwise and thinly sliced
- 1 tbsp unsalted butter
- 3 garlic cloves, thinly sliced
- 4 cups (960 ml) low-sodium vegetable or chicken broth
- 1 cup (240 ml) water, plus more as needed for thinning
- 3 fresh thyme sprigs
- 1 bay leaf (optional)
- 1 tsp kosher salt, plus more to taste
- 1/2 tsp freshly ground black pepper, plus more to taste
For Finishing
- 1/2 cup (120 ml) heavy cream, plus 1–2 tbsp extra for swirling on top
- 1–2 tsp fresh lemon juice (optional, for brightness)
- Fresh thyme leaves, for garnish
- Extra freshly ground black pepper, for garnish
Optional Toppings
- Toasted pumpkin seeds or sunflower seeds
- Garlic croutons
- A drizzle of good-quality extra-virgin olive oil
Step-by-Step Instructions
Step 1: Heat the oven and prep the vegetables
Preheat your oven to 400°F (200°C). Line a baking sheet with parchment paper if you like for easier cleanup. Peel the parsnips and cut them into roughly 1-inch chunks so they roast evenly. Trim the dark green tops and root ends from the leeks. Slice the leeks in half lengthwise, then fan the layers under cool running water to rinse out any grit or sand. Pat dry and slice the white and light green parts into thin half-moons. Peel the garlic and slice it thinly; set aside (you will add it later so it does not burn).
Step 2: Roast the parsnips until golden and sweet
Place the parsnip chunks on the baking sheet. Drizzle with 2 tablespoons olive oil and season with about 1/2 teaspoon salt and a few grinds of black pepper. Toss to coat and spread into a single layer with a little space between pieces so they caramelize instead of steam. Roast for 25–30 minutes, turning once halfway through, until the parsnips are tender, lightly browned, and smell sweet. Remove from the oven and set aside.
Step 3: Gently sauté the leeks and garlic
While the parsnips roast, heat the remaining 1 tablespoon olive oil and 1 tablespoon butter in a large, heavy-bottomed pot over medium heat. When the butter has melted and begins to foam, add the sliced leeks and a pinch of salt. Cook, stirring frequently, for 8–10 minutes until the leeks are very soft and translucent but not browned; lower the heat if they start to color. Add the sliced garlic and cook for 1–2 minutes more, just until fragrant. Avoid browning the garlic, as it can turn bitter.
Step 4: Add roasted parsnips, broth, and herbs
Transfer the roasted parsnips to the pot with the leeks and garlic. Pour in the broth and 1 cup (240 ml) water. Add the thyme sprigs and bay leaf if using. Stir to combine, scraping up any bits stuck to the bottom of the pot. Increase the heat to bring the mixture just to a boil, then immediately reduce to a gentle simmer. Cover partially with a lid and cook for 15–20 minutes, until the parsnips are very soft and the flavors have melded.
Step 5: Blend the soup until perfectly smooth
Remove the thyme sprigs and bay leaf from the pot. Turn off the heat. Use an immersion blender to purée the soup directly in the pot until it is completely smooth and velvety. Take your time here; the smoother you blend, the more luxurious the texture will be. If you are using a countertop blender, let the soup cool slightly, then carefully blend in batches, filling the blender no more than halfway and venting the lid so steam can escape. Return the blended soup to the pot.
Step 6: Stir in cream and adjust seasoning and texture
Return the pot to low heat. Stir in the 1/2 cup (120 ml) heavy cream. If the soup is thicker than you like, add more hot water or broth a little at a time until it reaches your preferred consistency. Taste and season with more salt and black pepper as needed. For a brighter flavor, stir in 1–2 teaspoons fresh lemon juice. Warm gently until heated through, but do not let it boil hard after adding the cream.
Step 7: Garnish and serve
Ladle the hot soup into warm bowls. Drizzle a small swirl of heavy cream over each serving and use the tip of a knife or a toothpick to gently feather it into a simple pattern if you like. Sprinkle with fresh thyme leaves and a little extra black pepper. Add any optional toppings, such as toasted seeds, croutons, or a light drizzle of olive oil. Serve immediately while steaming and fragrant, ideally with crusty bread for dipping.
Pro Tips
- Clean leeks thoroughly. Dirt hides between the layers. Always split them lengthwise and rinse well under running water before slicing.
- Roast for flavor. Roasting the parsnips first deepens their natural sweetness and adds gentle caramelized notes that make this soup taste restaurant-worthy.
- Blend very well. For the silkiest texture, blend longer than you think you need to. If you want it ultra-smooth, pass the blended soup through a fine-mesh sieve.
- Adjust thickness at the end. Parsnips can vary in starchiness. Keep extra hot water or broth handy and thin the soup after blending until it is just how you like it.
- Control the heat with cream. Once the cream is added, keep the soup below a full boil to prevent separation and maintain a smooth, velvety finish.
Variations
- Dairy-light or dairy-free: Replace the heavy cream with half-and-half for a lighter version, or use full-fat coconut milk or an unsweetened oat cream alternative for a dairy-free option.
- Parsnip–potato blend: Swap 8 oz (225 g) of the parsnips for 8 oz peeled Yukon Gold potatoes for a slightly milder, ultra-creamy soup.
- Extra herby: Add a small handful of fresh parsley or tarragon leaves when blending for a greener, more herb-forward flavor profile.
Storage & Make-Ahead
Allow the soup to cool to room temperature, then transfer to airtight containers. Refrigerate for up to 4 days. Reheat gently on the stovetop over low to medium heat, stirring often and avoiding a hard boil, especially once cream has been added. For best texture when freezing, freeze the soup before adding the cream: cool completely, then freeze in airtight containers or freezer bags for up to 3 months. Thaw overnight in the refrigerator, reheat, then stir in the cream just before serving. You can also roast the parsnips and sauté the leeks a day ahead; store them separately in the fridge and finish the soup the next day.
Nutrition (per serving)
Approximate values per serving (1 of 4): about 280–320 calories; 6–8 g protein; 32–38 g carbohydrates; 13–16 g fat; 5–7 g fiber; 6–8 g sugar (mostly natural from the vegetables). Actual values will vary based on specific brands of broth and cream and any optional garnishes used.
