Ingredients

• 4 pounds mussels (preferably cultivated), cleaned and steamed , then shucked
• 2 pounds plum tomatoes, halved lengthwise, seeded, and halves cut into sixths
• 1/2 cup chopped fresh basil
• 1/2 cup crème fraîche
• 1/2 cup finely grated Parmigiano-Reggiano (1 oz)
• 2 large garlic cloves, 1 minced and 1 halved
• 1/2 teaspoon salt
• 1/4 teaspoon black pepper
• 15 (1/3-inch-thick) slices from a baguette
• 2 tablespoons extra-virgin olive oil

Instructions

1. Preheat oven to 450°F.
2. Toss together mussels, tomatoes, basil, crème fraîche, cheese, minced garlic, salt, and pepper in an oiled 3-quart (about 13- by 9 1/2- by 2-inch) baking dish.
3. Rub 1 cut side of each bread slice with halved garlic and arrange bread, garlic side up, over mussel mixture in baking dish. Brush tops of bread with oil.
4. Bake gratin in middle of oven until bread is golden brown on top, about 15 minutes.
5. Serve mussels spooned over garlic toasts.