Silky Leek and Potato Soup with Cheddar Toasts

Why You’ll Love This Recipe

• Comfort in a bowl: silky, cozy, and deeply aromatic from butter-sweated leeks and thyme.
• Reliable texture: blending yields a restaurant-smooth finish every time.
• Balanced flavor: a hint of lemon brightens the creaminess without weighing things down.
• Irresistible side: crisp, melty cheddar toasts designed for dunking.

Grocery List

• Produce: Leeks, garlic, Yukon Gold or Russet potatoes, fresh thyme, lemon, chives (optional), bay leaf.
• Dairy: Unsalted butter, heavy cream, sharp cheddar.
• Pantry: Olive oil, low-sodium chicken or vegetable stock, baguette or sourdough, fine sea salt, black pepper, paprika (optional).

Full Ingredients

For the Soup

• 3 tbsp (42 g) unsalted butter
• 1 tbsp (15 ml) olive oil
• 3 large leeks, white and light green parts only, trimmed, halved lengthwise, thoroughly rinsed, and thinly sliced (about 6 cups / 600 g)
• 2 garlic cloves, thinly sliced
• 1.5 lb (680 g) Yukon Gold or Russet potatoes, peeled and cut into 1-inch chunks
• 6 sprigs fresh thyme (or 1 tsp dried thyme)
• 1 bay leaf
• 5 cups (1.2 L) low-sodium chicken or vegetable stock
• 1/2 cup (120 ml) heavy cream, plus more for swirling
• 2 tsp fresh lemon juice
• 1 to 1 1/4 tsp fine sea salt, to taste
• 1/2 tsp freshly ground black pepper, plus more to finish

For the Cheddar Toasts

• 8 slices baguette (1/2-inch thick) or 4 slices sourdough, halved
• 2 tbsp (28 g) unsalted butter, softened
• 1 cup (100 g) sharp cheddar, coarsely grated
• Pinch of sweet paprika or a smear of Dijon mustard (optional)

To Finish and Garnish

• 2–3 tbsp heavy cream, for swirling
• 2 tbsp finely snipped chives or parsley (optional)
• Extra thyme leaves and black pepper, to taste

Step-by-Step Instructions

Step 1: Prep and clean the leeks

Trim off the dark green tops of the leeks and the root ends. Halve lengthwise, then fan out the layers and rinse under cold running water to remove hidden grit. Slice thinly. Peel and dice the potatoes into 1-inch chunks. Slice the garlic. This ensures even cooking and an ultra-smooth blend later.

Step 2: Gently sweat leeks with butter and thyme

In a large heavy pot or Dutch oven, melt the butter with the olive oil over medium-low heat. Add the leeks, garlic, and 1/2 teaspoon salt. Cook, stirring occasionally, for 12–15 minutes until the leeks are soft, glossy, and sweet but not browned. Nestle in the thyme sprigs and bay leaf during the last minute to release their aroma.

Step 3: Simmer with potatoes and stock

Add the potatoes to the pot and pour in the stock. Increase heat to bring just to a boil, then reduce to a gentle simmer. Cook uncovered for 18–20 minutes, until the potatoes are fully tender and easily crushed against the side of the pot. Remove and discard the thyme sprigs and bay leaf.

Step 4: Blend silky-smooth

For the safest, smoothest result, blend the soup until perfectly velvety. Use an immersion blender directly in the pot until completely smooth, 2–3 minutes. Or carefully ladle hot soup into a stand blender, filling it only halfway, vent the lid, and cover with a towel; blend in batches until silky. Return the soup to the pot and re-warm over low heat.

Step 5: Make the cheddar toasts

While the soup simmers or blends, heat the oven to 400°F (200°C). Lay bread on a baking sheet, spread with softened butter, and top with an even layer of cheddar. Add a sprinkle of paprika or smear of Dijon if you like. Bake 6–8 minutes, until the cheese is melted and bubbling and the edges are crisp and golden.

Step 6: Finish, season, and serve

Stir the heavy cream and lemon juice into the soup and warm gently for 1–2 minutes—do not let it boil after adding cream. Taste and season with additional salt and black pepper as needed. Ladle into warm bowls, swirl a little extra cream on top, and garnish with chives and a few thyme leaves. Serve immediately with the hot cheddar toasts for dunking.

Pro Tips

• Clean leeks thoroughly: grit hides between layers. Halve lengthwise and rinse well, or soak slices in a bowl of cold water, swish, and lift out.
• Keep the heat gentle while sweating: leeks should soften without browning to preserve their sweet, delicate flavor and the soup’s pale color.
• Use floury potatoes (Yukon Gold or Russet) for a creamier texture; waxy potatoes won’t blend as silky.
• Blend completely: an immersion blender is easiest, but a high-speed blender yields the glossiest finish—just vent the lid and blend in batches for safety.
• Season after blending: the flavor concentrates as you puree; finish with lemon for brightness and adjust salt once the cream is in.

Variations

• Smoky bacon twist: Crisp 4 slices of bacon, use 1–2 tbsp bacon fat in place of olive oil, and sprinkle some crumbled bacon over bowls. Try smoked cheddar on the toasts.
• Vegan and dairy-free: Sweat leeks in 3 tbsp olive oil, use vegetable stock, and finish with 1/2 cup cashew cream or coconut cream. Top bread with a good vegan cheddar or serve with herb croutons.
• Chunky style: Reserve 1 cup diced potatoes; simmer separately until tender. Blend the soup as directed, then stir the reserved potatoes back in for texture.

Storage & Make-Ahead

Refrigerate soup (without the cream, if possible) in an airtight container for up to 4 days. Reheat gently over low heat; add cream and lemon after reheating and do not boil. Freeze (without cream) for up to 3 months; thaw overnight in the fridge, reheat slowly, then stir in cream and lemon. Cheddar toasts are best fresh but can be assembled ahead and baked at the last minute; re-crisp leftovers at 375°F (190°C) for 5–7 minutes.

Nutrition (per serving)

Approximate: 580 calories; 33 g fat; 56 g carbohydrates; 13 g protein; 5 g fiber; 900 mg sodium. Values will vary based on specific brands and bread used.