In a large pot, boil water and cook pasta until al dente according to package directions; drain and reserve ½ cup of pasta water. Toss pasta with ½ tablespoon of olive oil to prevent it from sticking.

In a large sauté pan, heat the butter and the remaining olive oil over medium heat. When it begins to foam, add the shallots, and cook, stirring occasionally, until tender, about 3 to 4 minutes. Add the garlic, and cook, stirring often, until fragrant, about 30 seconds. Season with salt, pepper and red pepper flakes if using.

Add the wine, bay leaves and mussels, and cover pan. Steam until mussels open halfway, about 5 minutes. Stir the mixture and add the milk. Cover and steam until mussels have opened fully, about 2 minutes. Discard any mussels that do not open. Remove the pan from heat and measure out about ½ cup of the pan juices in a heat-safe bowl to temper the eggs with.

In a medium bowl, whisk the eggs until light and frothy. Add the lemon juice to the eggs in a steady slow stream while whisking vigorously. Then, add the reserved pan juice in a steady slow stream while continuing to whisk the mixture vigorously.

Pour the egg mixture in the pan with the mussels in a steady slow stream, stirring constantly to coat the mussels in a lightly thickened sauce. Return the pan to low heat (do not allow the liquids to boil).

Gradually stir in the pasta in small batches and toss to coat with the sauce; add reserved pasta water as needed to loosen up the sauce. Add the dill and parsley and toss to combine. Serve immediately with extra lemon wedges.