Hollandaise Sauce for Eggs Benedict

In a heatproof bowl or the top of a double boiler set over a pan of simmering water, whisk egg yolks with water, whisking vigorously, until mixture thickens, about 4 minutes. Remove from heat, and stir in lemon juice.

Slowly whisk in melted butter until thickened. Season with salt. Serve sauce immediately, or keep warm over very gently simmering water, whisking occasionally.