Fish Soup with Lemon Aioli
- 2 tablespoons olive oil
- 1 small onion, finely chopped
- 2 baking potatoes, (8 ounces each), peeled and cut into 1/2-inch cubes
- 1 small bulb fennel, (about 10 ounces with stalks), trimmed, halved lengthwise, cored, and cut into 1/2-inch dice, fronds reserved for garnish (optional)
- Coarse salt and ground pepper
- 1 cup dry white wine
- 1 bottle (8 ounces) clam juice
- 4 large egg yolks
- 1 pound skinless cod fillet, or other white fish, cut into 1 1/2-inch chunks
- 4 thick slices crusty bread, lightly toasted, for serving
- Lemon Aioli, for serving
In a large saucepan, heat oil over medium. Add onion, potatoes, and fennel; season with salt and pepper. Cook, stirring frequently, until onion has softened, about 10 minutes (do not allow vegetables to brown).
Add wine, increase heat to medium-high, and cook until liquid has nearly evaporated, 5 to 7 minutes.
Add clam juice and 3 cups water. Bring to a boil, then reduce to a simmer; cook until potatoes are tender, 10 to 12 minutes.
In a small bowl, whisk egg yolks. Whisking constantly, gradually ladle about 1 cup of hot liquid from saucepan into yolks; add mixture to pan. Add fish, and simmer gently until fish is opaque and soup is slightly thickened (do not boil), 4 to 5 minutes. Season with salt and pepper.
Ladle soup into serving bowls; garnish with fennel fronds, if desired. Spread toasted bread with Lemon Aioli, and serve alongside soup.