Fishermen’s Soup

Put fish, potatoes, and pepper to taste into a medium pot. Add enough water to cover fish (about 5 cups) and bring to a boil over high heat, skimming foam as it rises to the surface. Reduce heat to medium-low and simmer for 1 hour.

Meanwhile, crush garlic and 1 tbsp. salt together with a mortar and pestle to a coarse paste. Gradually drizzle in oil, stirring and crushing constantly with the pestle until a smooth paste forms. Set garlic paste aside.

Working in small batches, put soup mixture (heads, bones, and all) into a food processor and pulse 5–7 times or until mixture is coarsely ground. Pass soup through a food mill into a large bowl, pressing as much of the solids through as possible. Finally, purée soup in a blender until smooth. Return soup to pot and heat over medium heat until hot. Whisk garlic paste into soup and adjust seasonings. Whisk egg yolk and vinegar together in a small bowl, whisk a ladleful of the hot soup into the egg mixture, then stir egg mixture back into soup. Do not allow soup to boil; it will curdle.

To serve, put 3 croutons into each of 4–6 soup bowls, top each crouton with some cheese, then ladle soup into bowls.