Prepare the hollandaise by whisking the egg yolk, Greek yogurt, lemon juice, and Dijon mustard in a small heat-proof glass bowl until completely smooth.
Place the bowl over a small pot of simmering water, ensuring the bottom of the bowl does not touch the water, and whisk constantly for 3-5 minutes until the sauce thickens.
Remove the sauce from heat and stir in the sea salt and cayenne pepper, then set aside in a warm spot.
Fill a medium saucepan with water and the white vinegar, bringing it to a very gentle simmer.
Crack each egg into a small ramekin, create a gentle vortex in the simmering water with a spoon, and drop the eggs in to poach for exactly 3 minutes for a runny yolk.
While the eggs poach, split and toast the sprouted grain English muffin and lightly sear the Canadian bacon slices in a dry skillet over medium heat until warmed through.
To assemble, place two slices of Canadian bacon on each toasted muffin half, top with a poached egg, and spoon the warm yogurt hollandaise over the top.
Garnish with fresh chopped chives and a crack of black pepper before serving immediately.