In a medium saucepan add the wine, lemon juice, cream, and shallots over a medium high heat. Bring to a simmer.
Reduce the heat to medium and let it simmer for about 4-5 minutes until the liquid is reduced by about 75%.
Reduce the heat to the lowest setting and whisk in 2 cubes of butter. Keep stirring until the butter is completely melted and combined.
Add a few more cubes, whisking continuously so the butter is combined well into the mixture. Continue to add remaining butter, a few cubes at a time, until the sauce has a thick, smooth texture, about 4 to 6 minutes.
Remove the saucepan from heat. Season with cayenne pepper and salt to taste.