Combine the shallots, white wine, and lemon juice in a 3-quart saucier set over high heat. Cook, whisking occasionally, until the mixture has reduced to about 3 tablespoons, 8 to 10 minutes.
Add the cream to the reduction. Once the liquid bubbles, reduce heat to low.
Add the butter, one cube at a time, whisking first on the heat and then off the heat. Whisk until each cube of butter has almost melted before adding another cube. Continue whisking butter into the reduction until the mixture is fully emulsified and has reached a rich sauce consistency.
Season with salt and white pepper, to taste. Store beurre blanc in a thermos until ready to serve.