2Place wine, lemon juice, cream, and shallots in a saucepan. Bring to a simmer over medium-high heat. Reduce heat to medium and let simmer until liquid is reduced by about 75%, 4 to 5 minutes.
3Reduce heat to the lowest setting and whisk in 2 cubes butter. Keep butter moving until it completely melts. Add a few more cubes, whisking continuously so butter emulsifies into wine-lemon juice mixture.