Fill a medium saucepan with water and add the white vinegar; bring to a gentle simmer over medium heat.
In a small heat-proof glass bowl, whisk the single egg yolk and lemon juice until the mixture doubles in volume.
Place the bowl over a pot of barely simmering water to create a double boiler, ensuring the bottom of the bowl does not touch the water.
Slowly drizzle the melted butter into the yolk mixture while whisking vigorously and constantly until the hollandaise is thick and velvety.
Remove the sauce from heat, stir in the cayenne pepper and a pinch of sea salt, and cover to keep warm.
Split the English muffin and toast both halves until the edges are golden brown and crisp.
In a small skillet over medium-high heat, sear the Canadian bacon slices for 1-2 minutes per side until warmed through and slightly caramelized.
Crack each of the two eggs into separate small ramekins; create a gentle whirlpool in the simmering vinegar water and carefully drop the eggs in.
Poach the eggs for exactly 3 minutes for a runny yolk, then remove with a slotted spoon and drain on a paper towel.
Assemble by placing the toasted muffins on a plate, layering with the seared Canadian bacon, and topping each with a poached egg.
Generously spoon the warm hollandaise over the eggs and garnish with minced fresh chives and black pepper.