In a small bowl, whisk together the Greek yogurt, egg yolk, lemon juice, and Dijon mustard until smooth.
Place the yogurt mixture in a heat-safe bowl over a pot of simmering water and whisk constantly until the sauce is warm and slightly thickened.
Season the sauce with sea salt and black pepper, then remove from heat and set aside.
Bring a medium pot of water to a gentle simmer and add the white vinegar.
Crack each egg into a small ramekin, then gently slide them into the simmering water, poaching for 3-4 minutes until the whites are set but the yolks remain runny.
While the eggs poach, toast the English muffin halves until golden brown and lightly sear the Canadian bacon in a dry skillet over medium heat.
Place two halves of the toasted muffin on a plate, top each with the seared Canadian bacon and a poached egg.
Drizzle the creamy yogurt hollandaise over the eggs and garnish with freshly chopped chives.