Begin by melting the unsalted butter in a small saucepan over low heat, then set aside to cool slightly. Separate two egg yolks into a heatproof bowl for the hollandaise. Measure your lemon juice. Fill a medium pot with about 3-4 inches of water for poaching, add 1 tablespoon white vinegar and a pinch of salt, and bring to a gentle simmer over medium-high heat. Cook the Canadian bacon in a skillet until lightly browned and warmed through, then keep warm. Toast the English muffins until golden brown.

Place the bowl with egg yolks and lemon juice over the simmering poaching water (creating a double boiler, ensuring the bowl doesn't touch the water). Whisk vigorously until the mixture thickens and lightens in color, about 3-5 minutes. Slowly drizzle in the melted butter, whisking continuously, until the sauce is thick and emulsified. Season with salt and pepper to taste. Remove from heat and keep warm, but do not let it get too hot.

Ensure the poaching water is at a gentle simmer, not a rolling boil. Create a gentle swirl in the water with your slotted spoon. Carefully crack each of the four eggs into separate ramekins or small bowls. Gently slide each egg into the simmering water. Poach for 3-4 minutes for a runny yolk, or longer for a firmer yolk. Do not overcrowd the pot; poach in batches if necessary.

While the eggs are poaching, arrange the toasted English muffin halves on serving plates. Place two slices of the cooked Canadian bacon on top of each English muffin half. This creates the sturdy and flavorful base for your Eggs Benedict. Keep them warm if needed while waiting for the eggs to finish.

Using a slotted spoon, carefully remove the poached eggs from the water, draining any excess liquid. Gently place two poached eggs on top of the Canadian bacon on each English muffin half. Generously spoon the warm hollandaise sauce over the eggs, ensuring a beautiful cascade. Garnish with freshly chopped chives and a crack of fresh black pepper. Serve immediately and enjoy!