- 3 russet potatoes (peeled, if desired)
- 3 tablespoons olive oil
- 1 1/2 teaspoons kosher salt
- 1/2 teaspoon black pepper
- 4 tablespoons unsalted butter
- 2 cloves garlic, thinly sliced
- 2 leeks (white and light green parts), halved lengthwise and thinly sliced into half-moons
- 1 cup dry white wine, such as Sauvignon Blanc
- 4 Roma (plum) tomatoes, seeded and diced
- 2 pounds mussels, scrubbed
- Heat oven to 400° F.
- Cut the potatoes into French fry–size strips. Place on a baking sheet. Drizzle with the oil, season with 1/2 teaspoon of the salt and 1/4 teaspoon of the pepper, and toss. Spread in a single layer. Roast until golden and crisp, 45 to 50 minutes.
- Meanwhile, melt the butter in a large pot over medium heat. Add the garlic and cook for 1 minute. Add the leeks and cook until softened, 4 to 5 minutes. Add the wine, tomatoes, and the remaining salt and pepper. Bring to a boil. Cook for 2 minutes. Add the mussels, cover, and cook until they open, about 3 minutes. Discard any mussels that remain closed.
- Divide the mussels and cooking liquid among individual bowls. Serve with the fries and an extra bowl for the discarded shells.