Bring wine, vinegar, shallot, and salt to boil in small, heavy-bottomed saucepan over medium-high heat. Reduce heat to medium-low and simmer until reduced by two-thirds, about 5 minutes. Whisk in cream. Add butter, 1 piece at a time, whisking vigorously after each addition until butter is incorporated and forms thick, pale yellow sauce, 30 to 60 seconds. Remove pan from heat and serve.

Makes about 2/3 cup