Moules gratinées en persillade

Mussels with parsley and garlic

Mussels on the half shell baked with garlicky parsley butter make a delightful start to a meal — either as an amuse-bouche (palate teaser) at cocktail hour or as a first course.

Preparation is easy but it does take time. First, you clean the mussels and steam them open. Then you make the parsley butter. Finally you bake the mussels until the filling is bubbly and golden. Total preparation time is about 40 minutes.

This recipe may be made with large mussels (moules d’Espagne) or smaller ones (moules de bouchot), but preferably not too small. Get the freshest mussels available. The key to success is not to overcook the mussels, both when steaming and baking.

The filling includes breadcrumbs (chapelure). I make my breadcrumbs by crushing biscottes (similar to unflavored melba toast) with a rolling pin. Alternatively, you can buy readymade breadcrumbs or make them from dried bread.

If you end up with more butter-filled mussels than you plan to serve, not a problem — you can freeze them, and defrost and bake them on another occasion.

1/2 pound (250 g) mussels (equivalent to 1 pint / 1/2 liter)
4 tbsp. (60 g) butter at room temperature
1 clove garlic
1 bunch fresh parsley, preferably flat leaf
1/4 tsp. salt (only if using unsalted butter)
freshly ground black pepper
4 tbsp. breadcrumbs (chapelure)

Clean the mussels to remove the beards: Immerse them in a bowl of water. Grasp a mussel. Find the beard along the flat edge, pull it off, transfer to a colander. Repeat until you’ve cleaned all the mussels. Important: if a mussel’s shell is broken or open, discard it. Once all the mussels are in the colander, rinse under running water.

Pour a very thin layer of water into a large pot — it should be only 1/8-inch (3 mm) deep. Bring to a boil over a high flame. Add the mussels. Cover the pot. Cook just until the mussels open, about 1 minute. Remove from heat and allow to cool for easy handling.

Preheat the oven to 210 C (400 F, gas mark 7).

Place the butter on a plate. Cut it into a few pieces to help it soften up.

Peel and halve the garlic. Put through a press over the plate.

Pull the parsley leaves off the stems. Mince finely until you have 4 tbsp. Add to the plate.

Using a fork, mash the butter, garlic and parsley together. Add the salt (only if using unsalted butter) and grind on some black pepper.

Add the breadcrumbs. Mash well to create a homogenous spread.

You will now fill the mussels with the parsley butter, in batches.

Remove and discard the top shell of each mussel. Transfer the mussels on the half shell to a board. When you’ve done about 20 mussels, fill them with the butter spread, as shown in the photo.

Line a baking pan (such as a pie tin) with parchment paper. Set the filled mussels on top.

Bake for about 5 minutes, until the butter is bubbly.

Repeat with the rest of the mussels.

Serves 4 as a starter, and 8 as finger food at cocktail hour.