Clean leeks: Remove dark green tops, slice lengthwise, rinse thoroughly, and chop.
Sauté leeks: Heat olive oil in a large pot over medium heat. Add leeks and a pinch of salt; cook until softened (8–10 min).
Add garlic: Cook for 1 min until fragrant.
Add potatoes & broth: Add cubed potatoes, broth, and bay leaf. Bring to boil, then simmer 15–20 min until potatoes are tender.
Season: Remove bay leaf, stir in salt and pepper.
Blend: Use immersion blender until smooth (or blend in batches carefully).
Adjust consistency: Add more broth if needed.
Taste & adjust: Add more seasoning or a splash of lemon juice.
Serve: Garnish with parsley, chives, croutons, or olive oil.