Potato-Leek Soup with Roasted Garlic (No Milk or Cream)

Roast the garlic and potatoes
0 Heat the oven to 425 (220 C) degrees.
1 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, 20-25 minutes. (The roasted garlic can be prepared up to 5 days ahead. Store in the refrigerator in a covered container).
2 Put 2 cups of the potatoes on a baking sheet. Add 2 tablespoons olive oil and ½ teaspoon salt and toss around to coat.  Put them in the oven next to the garlic, and roast until tender, 25-30 minutes.
Make the soup
3 Meanwhile, heat a tablespoon of olive oil in a Dutch oven or large saucepan over medium-high heat. Add the leek and cook until softened. Add the roasted garlic, remaining raw potatoes, 6 cups broth and 1 teaspoon salt. Bring to a simmer and cook until the potatoes are tender, about 25 minutes.
4 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 ¼ cup of the Parmesan cheese and the lemon juice.
5 To serve, put 4 or 5 roasted potatoes in each serving bowl. Ladle the soup over the potatoes. Sprinkle with additional cheese and the parsley.