Make the Hollandaise Sauce - Place egg yolks, water, and vinegar in a medium stainless steel mixing bowl. Fill a small saucepan with about 2 inches of water and bring to a simmer. Place the bowl on top of the saucepan without it touching the water and whisk continuously until the eggs thicken, about 3 minutes. Remove the bowl from the saucepan and whisk in lemon juice to stop cooking. In a medium skillet, melt the butter over low heat. It should be warmed to 140 to 145ºF (60 to 63ºC) when added to the egg yolk mixture. Nestle the bowl containing the egg mixture in a kitchen towel. Slowly add a few drops of melted butter while constantly whisking. Gradually add more butter, whisking until all is incorporated. The sauce should be thick. Add salt and cayenne pepper to taste. Set aside. Rewarm if needed for serving.
Poach the Eggs - Add 2 quarts of water to a medium saucepan. Heat over medium-high heat. Once simmering, reduce to medium-low heat and stir in the vinegar and salt (if using). Hold the temperature between 180 and 190°F (82 and 88°C) on an instant-read thermometer, adjusting the heat as needed.Crack one egg into a small bowl or ramekin, then carefully slide it into the water. Slowly stir at the edges of the pot for 10 seconds. Cook until whites are set, 3 to 5 minutes. Use a slotted spoon to transfer the egg to a paper towel-lined plate. Repeat the process with the remaining eggs.
Cook the Bacon - Heat a large skillet over medium heat. Lightly grease the pan with butter or cooking oil. Sear the Canadian bacon, for 1 to 2 minutes per side.
Assemble - Toast the English muffins and top each half with a slice of Canadian bacon, poached eggs, and hollandaise sauce. Garnish with a sprinkling of paprika and chopped chives.
Notes
Batch Cooking Eggs:To poach 4 eggs, add them to the saucepan one at a time, evenly spacing out. Do not stir. Let them cook for about 3 to 5 minutes.
Keeping Eggs Warm:Heat a separate pot of water over low heat, keeping it between 120 and 140ºF (49 and 60ºC). Add the poached eggs and keep warm for no more than 20 minutes.
Storing: Hollandaise sauce can be refrigerated for up to 3 days.
Reheating:Place hollandaise sauce in a double boiler, whisking until warm.