Using a sharp chef's knife and cutting board, chop the leek stalks into thick pieces. Rinse thoroughly under cold water to remove any grit.
2 large potatoes
Set a large soup pot over medium heat. Add the butter and let it melt until bubbling gently, releasing a faint aroma of butter and leek.
2 large potatoes
Add the chopped leek stalks to the pot. Sauté for about 5-7 minutes, stirring occasionally, until they become translucent and fragrant with some light browning around the edges.
2 large potatoes
Add the diced potatoes to the pot. Stir to coat them with the butter and leek mixture, then pour in the vegetable broth. Increase heat and bring to a gentle simmer.
2 large potatoes
Simmer uncovered for 20-25 minutes, or until the potatoes are very tender and can be easily pierced with a fork. The liquid should slightly reduce and thicken.
Using an immersion blender or carefully transferring the soup to a blender, puree until smooth and velvety. Return to the pot if needed, season with salt and pepper, and heat through for 2-3 minutes before serving.
2 large potatoes