Step 1

Heat the oven to 400 (200C) degrees.

Step 2

Put the garlic cloves in a small baking dish. Drizzle with olive oil, sprinkle with a pinch of salt and cover with a piece of foil. Roast until the cloves are soft and golden brown, 25-30 minutes.

Step 3

Put 2 cups of the potatoes on a baking sheet. Add 2 tablespoons olive oil and 1/2 teaspoon salt and toss around to coat. Roast in the oven alongside the garlic until tender, about 40 minutes.

Step 4

Heat a tablespoon of olive oil in a large pot or saucepan over medium-high heat. Add the leek and cook until softened. Add the roasted garlic, remaining raw potatoes, 6 cups water or broth and 1 teaspoon salt. Bring to a simmer and cook until the potatoes are tender, about 25 minutes.

Step 5

Puree the soup with a hand blender or in a regular blender in batches (let it cool 10 minutes before putting in the blender) until smooth. Stir in 1/4 cup of the parmesan and the lemon juice.

Step 6

To serve, put 4 or 5 roasted potatoes in each serving bowl. Ladle the soup over the potatoes. Sprinkle with additional cheese and some of the herbs.