Mussels Dijon

Mussels Dijon is the French bistro classic that takes basic moules marinière and steers it sharper. The familiar steam-in-white-wine approach gives way to something bolder: a generous slug of Dijon mustard and heavy cream reduces with the wine and shellfish liquor into a glossy, sharp-tangy sauce that coats every mussel.

Debearding is the prep step nobody loves but everyone has to do. The byssus (the wiry brown fibers attached to one side of the shell) needs to come off before cooking. Pinch it firmly and pull toward the hinge of the shell. Discard any mussels that are open and don’t close when tapped; they’re dead and not safe to eat.

The steam time is critical. Three to five minutes covered until the shells just open is plenty. Once they pop, they’re done. Any longer and they turn rubbery. Discard any mussels that don’t open after cooking; they were already dead.

A full cup of Dijon mustard sounds aggressive, but in a sauce with two cups of cream and a half cup of wine, it works. The mustard gives the sauce its identity. Use a real French Dijon (Maille or Edmont Fallot), not yellow ballpark mustard.

Reducing the sauce by half is what concentrates the flavors and thickens it enough to cling to the mussels. Don’t shortcut this step.

Serve with a crusty French bread for dunking. The sauce is the best part.

Pro Tips

• Buy mussels day-of cooking; they don’t keep well.
• Store mussels on ice in a colander, not submerged in water (which kills them).
• Use a heavy stockpot with a tight lid for proper steam build-up.
• Don’t pre-salt the sauce; mustard and mussel liquor are both salty.
• Pair with a glass of the same dry white wine you cooked with.

Variations

• Sub Pernod or pastis for some of the wine for anise notes.
• Add a pinch of saffron to the sauce for color and elegance.
• Stir in 2 tablespoons fresh tarragon at the end for an herbal twist.