Seared Scallops with Cilantro Lime Sauce

• 1 clove garlic, peeled

• 1 bunch cilantro, with stems cut off

• ½ cup grape seed oil

• 2 tablespoons red wine vinegar

• 2 tablespoons sour cream

• 2 tablespoons mayonnaise

• ¼ lime, peeled from skin

• ½ teaspoon kosher salt

• 12 U/10 fresh, dry-packed diver scallops

• ¼ teaspoon kosher salt

• 1 tablespoon European-style butter, salted

• 1 tablespoon grape seed oil