Bring a medium pot of water to a gentle simmer and stir in the white vinegar.
In a small heat-safe glass bowl, whisk together the single egg yolk, Greek yogurt, lemon juice, and Dijon mustard.
Place the bowl over the simmering water (ensuring the bottom does not touch the water) and whisk constantly until the sauce thickens slightly.
Slowly whisk the melted ghee, sea salt, and black pepper into the yogurt mixture until the sauce is smooth and warm, then remove from heat and cover to keep warm.
Sear the Canadian bacon in a dry skillet over medium-high heat for 1-2 minutes per side until the edges are golden and slightly crisp.
Crack the two whole eggs into individual small ramekins, then gently slide them into the simmering vinegar water; poach for 3 minutes until the whites are opaque but the yolks are still soft.
Toast the English muffin half until golden brown and place it on a serving plate.
Layer the seared Canadian bacon onto the muffin, carefully place the poached eggs on top, and pour the warm hollandaise sauce over the eggs.
Garnish with finely chopped fresh chives and serve immediately.