Cut leek in half lenght-wise and wash thoroughly between leaves. Drain and cut into slices. Peel potatoes and dice. Peel and slice garlic cloves.
Heat a pot on medium and add a tablespoon of olive oil. When heated, add sliced leek and stir-fry for a minute, until the leeks turn a bright green color. Then, add diced potatoes and garlic slices. Cook for another minute or two, stirring regularly to make sure the vegetables do not stick to the pot, then add vegetable stock. Season with salt and pepper to taste, add bay leaf and chopped parsley and cook until the potatoes turn soft. If needed, add more water while cooking.
When the vegetables are cooked, remove the bay leaf and puree with a stick blender until creamy. If the soup is too thick, add more water and blend quickly to combine. Taste the soup and season with more salt and pepper to taste.
Serve hot with a drizzle of olive oil and a sprinkle of chopped parsley.