2 medium potatoes (1 pound), peeled and cut into ½-inch chunks
4 cups vegetable broth
freshly ground black pepper, to taste
Directions
Start by cleaning the leeks: trim the root end, as well as 1 to 3 inches off the dark green part (just whatever looks bruised or dry), and discard. Halve the stalk lengthwise and cut into thin ½-moons. Place the chopped leeks in a big bowl of water and swirl around with your hands while separating the layers to release all the dirt. Lift the leeks out of the water and place back onto your cutting board. If the water looks really dirty, repeat the process with new water.
Heat the oil in a large, heavy-bottomed pot over medium heat. Add the leeks and salt, and cook until soft and bright green, about 10 minutes, stirring occasionally.
Add the garlic and thyme, and cook for another 30 seconds.
Next, add the potatoes and broth. Cover tightly with a lid and bring to a boil. Then, reduce the heat to low and simmer gently until the potatoes are cooked through, about 15 minutes.
Using an immersion blender, puree the soup until creamy. Season to taste with salt and pepper, then serve.