First make the hollandaise sauce. Using a large balloon whisk, beat the egg yolks with a squeeze of lemon juice and salt and pepper to taste in a bowl set over a pan of simmering water. Beat vigorously for about 10 minutes until the mixture thickens. (To make sure the sauce doesn’t overheat, take it on and off the heat while you whisk, scraping around the sides of the bowl with a plastic spatula.) The aim is to achieve a golden, airy sauce that forms ribbons on the surface when the whisk is lifted.