Customers protested when Claudio Pirollo tried to take this saucy gratin off his menu. And so it has remained unchanged. He serves it as an appetizer -- the garlic butter makes it quite rich -- and recommends pairing it with toasted slices of rustic bread, plus a light Belgian beer along the lines of Orval or Hoegaarden.
A key to success is to make sure your parsley is thoroughly dry; if moisture is present, it will cause the parsley to separate from the butter.
Make Ahead: You’ll have plenty of garlic butter left over; wrap well and freeze for up to 3 months.
Servings: 5 - 6
- For the garlic butter
- 8 ounces unsalted butter, preferably left overnight at room temperature (2 sticks)
- 2 to 3 medium cloves garlic, finely chopped (1 tablespoon)
- Leaves from 1 small bunch flat-leaf parsley, finely chopped
- Freshly squeezed juice from 1/4 lemon (1 teaspoon)
- 1/4 to 1/2 teaspoon salt, to taste
- For the mussels
- 2 tablespoons unsalted butter
- 8 tablespoons chopped onion (from 1/4 large onion)
- 2 ribs celery, chopped
- 1 medium clove garlic, chopped
- 3 bunches thyme
- 4 pounds mussels, preferably Blue Bay (from Prince Edward Island), cleaned and beards removed; see NOTE
- 1 1/2 to 2 teaspoons salt, for the cooking liquid, plus more for sprinkling on the mussels
- 4 cups white wine
- Coarse salt, for broiling
- Cayenne pepper
- 1/2 cup plain dried bread crumbs
- 1/2 cup freshly grated Parmesan cheese
For the garlic butter: Combine the softened butter, garlic, parsley, lemon juice and 1/4 to 1/2 teaspoon of the salt in the bowl of a food processor. Pulse a few times, until well blended; the mixture will be green. Don't over-blend, or the butter will melt and separate from the parsley. The yield will be about 1 1/4 cups. Refrigerate for 20 minutes to firm it up slightly.
For the mussels: Melt the butter in a large pot over medium heat. Add the onions, celery, garlic and thyme; cook for about 8 minutes, stirring occasionally, until the onion has softened.
Add the mussels to the pot, along with the 1 1/2 to 2 teaspoons salt and the wine. Increase the heat to medium-high and bring to a boil, then cover and cook for about 5 minutes, stirring just once, until it looks as if all the mussels have opened. Discard any mussels that have not opened.
Drain the liquid from the mussels. Discard the empty sides of the shells (keeping the meat intact on the other side of the shells). Cover 1 or 2 large rimmed baking sheets with a layer of coarse salt and arrange the mussels (in their shells) on the baking sheets in a single layer. (The coarse salt will keep the shells stable as the mussels broil.)
Position the top oven rack 4 to 6 inches from the top broiler element; preheat the broiler.
Sprinkle salt to taste over the mussels, along with a pinch or two of cayenne pepper.
Spoon about 1/4 teaspoon of the garlic butter onto each mussel. (Alternatively, you may transfer the garlic butter to a pastry bag or a resealable plastic food storage bag with one of the bottom corners snipped off; use the bag to pipe a line of butter onto each mussel.) Sprinkle the bread crumbs and Parmesan on top of the mussels.
Broil for about 5 minutes, until the butter melts and the crumbs take on a nice light-golden color.
Serve immediately, with rustic bread and bowls for discarding the shells.
NOTE: Before cooking, discard any mussels whose shells are cracked or gouged, or ones that do not close when lightly tapped.
Adapted from chef Claudio Pirollo of Et Voila! in Northwest Washington.
Tested by Nicole Schofer.
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