I found it on Epicurious - have been finding more there than anywhere lately, it seems.
I only had my homemade tarragon vinegar, so I went a little easy on the vinegar & a little heavier on the white wine, so that it wasn't to "tarragon-y". My cast iron skillet works great for searing - though I still dust a bit of flour on the scallops first, to get that nice golden color fast, without burning the butter or the scallops.
- 1 1/4 pounds large sea scallops, tough ligament from side of each discarded
- 7 tablespoons unsalted butter, cut into tablespoons, divided
- 2 tablespoons finely chopped shallot
- 1/4 cup dry white wine
- 1/4 cup white-wine vinegar
- 1 tablespoon finely chopped tarragon
Pat scallops dry and sprinkle with 1/4 teaspoon each of salt and pepper (total).
Heat 1 tablespoon butter in a 12-inch nonstick skillet over medium-high heat until foam subsides, then sear scallops, turning once, until golden brown and just cooked through, about 5 minutes total. Transfer to a platter.
Add shallot, wine, and vinegar to skillet and boil, scraping up brown bits, until reduced to 2 tablespoons. Add juices from platter and if necessary boil until liquid is reduced to about 1/4 cup. Reduce heat to low and add 3 tablespoons butter, stirring until almost melted, then add remaining 3 tablespoons butter and swirl until incorporated and sauce has a creamy consistency. Stir in tarragon and salt to taste; pour sauce over scallops.