Serves 4 to 6
1/3 cup plus 1/4 cup extra-virgin olive oil
1 cup chopped white onion
10 garlic cloves, smashed
1 teaspoon grated lemon zest (page 43)
6 to 8 cups Basic Stock (opposite)
6 russet (Idaho) potatoes
1/3 cup crème fraîche (optional)
The trouble with potato soup: how to keep it from getting gluey. I do this by roasting the potatoes first, to break down their starches, then using a food mill instead of a blender, which keeps them from becoming overprocessed and gummy.
1. Start a pot over medium heat with ⅓ cup of the olive oil, the onion, and the garlic (page 17).
2. Add the lemon zest, then pour in 6 cups of the stock. Bring to a boil, and let boil for 15 minutes, stirring occasionally. Remove from the heat and let cool to room temperature. Puree in a blender until silky.
3. Preheat the oven to its lowest temperature (150° to 200°F). Poke holes in the potatoes with a fork and wrap them in foil.
4. Roast the potatoes for 3 hours, until tender. Unwrap the potatoes and peel them. The skins should slide right off. Smash them onto a baking sheet in a layer about 1/2 inch thick, completely breaking them apart in the process. Pour the
remaining 1/4 cup oil over the potatoes and sprinkle them with 1 teaspoon salt.
5. Return the potatoes to the oven. Roast until they’re golden brown and have a crunchy crust, about 30 minutes.
6. Remove the potatoes from the oven, put them in a pot, and pour in 6 cups of the soup base. Cook over low heat, stirring occasionally, until the potatoes are very soft, 20 to 30 minutes. Remove from heat and let cool to room temperature.
7. Puree the potatoes in a food mill (not a food processor or blender) and push through a chinois (page 23) to remove lumps. Put the pureed potatoes in a pot.
8. Add additional soup base or Basic Stock (up to 2 cups) to thin the soup until it has a thick and creamy texture, if needed. Every potato is different—some are bigger, some are starchier, some are just plain weird—so adjust accordingly. Salt to taste.