Whisk the Greek yogurt, one egg yolk, lemon juice, Dijon mustard, sea salt, and cayenne pepper in a small heat-proof bowl.
Place the bowl over a small pot of simmering water (double boiler) and whisk constantly until the sauce is thickened and velvety.
Fill a medium saucepan with water and a splash of vinegar, bringing it to a very gentle simmer.
Crack the two whole eggs and three egg whites into separate small ramekins, then carefully slide them into the simmering water.
Poach the eggs for approximately 3 to 4 minutes until the whites are set but the yolks remain soft.
Split and toast the whole wheat English muffin until golden brown and crisp.
In a dry skillet over medium-high heat, sear the Canadian bacon slices for 1 minute per side until warmed and slightly caramelized.
Place two slices of Canadian bacon on each toasted muffin half, top with the poached eggs, and spoon the warm hollandaise sauce over the top.
Garnish with freshly snipped chives and a crack of black pepper before serving immediately.