- 4 generous slices country-style bread cut into cubes
- 1/3 cup grated Parmesan cheese
- 2 tablespoons olive oil
- 3/4 cup chopped fresh parsley
- 1/4 cup chopped fresh chives
- 1/4 cup chopped fresh tarragon
- 2/3 cup sour cream
- 3 tablespoons Dijon mustard
- 1 tablespoon whole grain brown mustard
- 3 tablespoons butter
- 4 large garlic cloves, minced
- 2 tablespoons chopped fresh thyme
- 5 pounds mussels, scrubbed and debearded
- 3 cups diced seeded tomatoes (about 4 large)
- 4 scallions, chopped
- 1 12-ounce bottle beer
- Preheat oven to 375°F. Combine bread cubes, Parmesan, and oil in medium bowl; sprinkle with salt and toss to coat. Spread bread cubes evenly on rimmed baking sheet. Bake until bread cubes are crisp and golden around edges, about 15 minutes. Remove from oven and cool.
- Mix parsley, chives, tarragon in small bowl. Whisk sour cream and both mustards in another small bowl to blend; set aside.
- Melt butter in extra-large pot with lid over high heat. Add garlic and thyme; stir 1 minute. Add tomatoes, and scallions and mustard mixture and stir. Add mussels, pour in the beer and grind on some black pepper.
- Cover tightly and cook until steam appears, about 3 minutes. Add half of fresh herb mixture and stir until mussels and herbs are gently mixed. Cover tightly again and cook until mussels open, 4 to 5 minutes (toss any mussels that do not open).
- Either pour mixture into one big bowl or divide among six individual bowls. Sprinkle each serving with Parmesan croutons and remaining herb mixture and serve.