Hollandaise sauce mayonnaise and Béarnaise, the egg does not coagulate as in a custard; rather, the lecithin in the eggs serves as an emulsifier, allowing the mixture of the normally immiscible butter and lemon juice to form a stable emulsion. To make hollandaise sauce, beaten egg yolks are combined with butter, lemon juice, salt, and water, and heated gently while being mixed. Some cooks use a double boiler in order to control the temperature. Some recipes add melted butter to warmed yolks; others call for unmelted butter and the yolks to be heated together; still others combine warm butter and eggs in
La Fête espagnole in Nice; Louis Nalpas agreed to back the production as long as it was shot there, though some additional material was filmed in the Basque border town of Hondarribia. For the duration of the shooting, which concluded in November, Delluc was only seen intermittently on the set. He was, however, fully involved in editing the film with Dulac. It was screened for critics on March 17, 1920, and went into release either March 31 or May 7, 1920. "La Fête espagnole" was widely praised by critics as something vital and new in French cinema, though—as observed by Tami Williams—with the