Verjus Sauce for Oysters

This variation on the classic mignonette sauce uses a white verjus in place of red-wine vinegar. Verjus, the unsweetened, unfermented juice of unripened wine grapes, gives the sauce a more mellow flavor. You can find verjus, which comes in red or white just like wine, at specialty grocery stores.

• 1 tsp. grapeseed or canola oil
• 2 Tbs. whole black peppercorns, preferably Tellicherry
• 1/4 tsp. salt, preferably sea salt
• 1 Tbs. finely minced fresh shallot
• 1 cup white verjus
• 2 Tbs. closely snipped fresh chives or chive blossoms

In a small, heavy-based skillet, heat the oil until very hot. Add the peppercorns, reduce the heat to medium low, and toast the peppercorns, swirling frequently, until aromatic, about 5 minutes. Pour the hot peppercorns onto a cutting board to cool. Using a blunt object (such as the bottom of a clean skillet or a meat mallet), crush the peppercorns coarsely but evenly. Put the crushed pepper into a nonreactive bowl and add the salt, shallot, and verjus. Stir well and then allow to steep for at least 30 minutes at room temperature or in the refrigerator; the sauce will darken over time. Pour a little verjus sauce on the grilled oysters and garnish with the snipped chives.