American
Make the hollandaise: whisk the egg yolks with lemon juice over a pan of barely simmering water until pale and thickened, then slowly stream in the melted butter, whisking, until glossy; season with salt and cayenne and keep warm.
Toast the split English muffins and lightly fry or warm the Canadian bacon in a dry pan.
Bring a wide pan of water to a gentle simmer and add the white wine vinegar.
Crack each egg into a cup, swirl the water, and slide the eggs in one at a time; poach for about 3 minutes until whites are set but yolks still soft.
Lift the poached eggs out with a slotted spoon and drain on paper towel.
Top each muffin half with bacon, then a poached egg.
Spoon warm hollandaise over the eggs, sprinkle with chives and a dusting of cayenne, and serve immediately.