In a non-stick skillet over medium heat, lightly warm the Canadian bacon for 1–2 minutes on each side until heated through. Set aside. Split the whole-grain English muffins and toast them until lightly browned.

Fill a medium saucepan with water and bring it to a gentle simmer. Add the vinegar. Crack each egg into a small bowl and gently slide it into the simmering water.

Poach for about 3–4 minutes for a runny yolk (or longer for firmer yolks). Remove the eggs with a slotted spoon and drain on paper towels.

In a heatproof bowl, whisk together the egg yolks, Greek yogurt, lemon juice, Dijon mustard, cayenne pepper, and a pinch of salt.

Place the bowl over a pot of simmering water and whisk continuously for 3–5 minutes until the sauce thickens slightly. Avoid overheating to prevent scrambling the eggs.