01 -
Slice leeks into 6 mm rounds and rinse thoroughly under running water to remove grit. Drain well.
02 -
In a heavy-bottomed pot, heat olive oil over medium-low. Add leeks, garlic, and thyme. Sauté gently until leeks are soft, golden, and aromatic, approximately 8–10 minutes.
03 -
Add sliced potatoes, stock, salt, and black pepper. Increase heat and bring to a boil. Cover, reduce to low, and simmer until potatoes are fork-tender, about 15–20 minutes.
04 -
While the soup simmers, prepare leek oil if desired by gently heating leek tops in oil then straining. Set aside for serving.
05 -
Once potatoes are tender, use an immersion blender to blend the soup until mostly smooth but still textured. Avoid over-blending to prevent a gummy consistency. Alternately, blend in batches using a blender, ensuring the container is never more than half full and the lid is firmly held with a towel.
06 -
Return blended soup to the pot and whisk in sour cream. Taste and adjust salt and pepper if necessary. Warm over low heat as needed.
07 -
Ladle soup into bowls. Drizzle with leek oil if using, and garnish with chives or scallions before serving.