Start the hollandaise: whisk the Egg Yolks with the Lemon Juice and a tablespoon of Water in a heatproof bowl until smooth.
Set the bowl over (but not touching) simmering water and whisk constantly until the mixture thickens and becomes ribbon-like, about 3–4 minutes.
Meanwhile, melt the Butter until hot and gently simmering; then remove the whisking bowl from the heat and very slowly drizzle the melted butter into the yolk mixture while whisking constantly to form a thick, glossy sauce.
Season the hollandaise with a pinch of Kosher Salt and a light dusting of Cayenne Pepper; keep warm over a pot of very gently simmering water or in a thermos so it stays fluid.
Prepare the bases: split and toast the English Muffins until golden, and in a skillet warm the Canadian Bacon over medium heat until lightly browned, about 1 minute per side.
Poach the Eggs: bring a wide pot of water to a gentle simmer, add a splash of White Vinegar and a pinch of kosher salt, stir to create a gentle whirlpool, then carefully slide in each egg and cook 3–4 minutes for runny yolks (longer if you prefer firmer yolks).
Remove the eggs with a slotted spoon and drain briefly on a paper towel.
Assemble: place the warmed Canadian bacon on each toasted muffin half, top with a poached egg, and spoon a generous amount of hollandaise over the top.
Finish with a small sprinkle of cayenne or extra kosher salt to taste and serve immediately while everything is warm and silky.
