Grilled Mussels with Salsa Verde

To prepare salsa verde: Place garlic in a small saucepan and cover with 1/2 inch of cold water. Bring to a boil over high heat. As soon as the water boils, drain, add 1/2 inch of water to the pan and bring to a boil again. Drain and rinse under cold water until cool enough to handle. Peel and coarsely chop.

Place the garlic, parsley, anchovies, capers, basil (or mint or tarragon) and lemon zest in a food processor or blender. With the motor running, slowly add oil until just blended. The sauce should still have a little texture. Season with salt and pepper; set aside.

To prepare mussels: Place mussels in a Dutch oven (or other large pot) along with wine, parsley and butter. Bring to a boil over high heat. Reduce heat to medium, cover tightly and cook, stirring once or twice, until the mussels open, 4 to 6 minutes. Transfer the mussels to a large bowl with a slotted spoon. (Discard any unopened mussels.) Pour the broth through a fine-mesh sieve and set aside.

Preheat grill to medium-high or position a rack in upper third of oven and preheat broiler.

Line a baking sheet (one that will fit on your grill, if grilling) with about 1/2 inch of rock salt, coarse salt or loosely crumpled foil to make a base for the mussels. (This will prevent them from tipping over.) When cool enough to handle, remove the top shell from each mussel. Loosen the meat from the shell with a paring knife or spoon. Place the mussels in their half shells on the prepared baking sheet. Add a scant teaspoon of the reserved broth to each, then top with a generous dollop of salsa verde. (Refrigerate or freeze the remaining mussel broth for another use.)

Just before you're ready to serve, place the baking sheet of mussels on the grill (or under the broiler) and grill (or broil) until the salsa begins to bubble and the mussels are heated through, about 5 minutes on the grill, 3 to 5 minutes under the broiler. Serve immediately.