Preheat the oven to 200° F.
Put the Canadian bacon in a large nonstick skillet. Set over a burner but do not turn on the burner. Put 2 ovenproof plates in the oven to warm.
Fill a medium nonstick skillet nearly to the rim with water. Add the kosher salt and vinegar and bring to a simmer over high heat. Alternatively, fill an egg poacher with water and season with salt.
To make the Hollandaise Sauce: Put the egg yolks, cream, the 1/4 tsp kosher salt, and cayenne in a blender. Blend on high speed until smooth and frothy, 2 to 3 seconds. With the blender still on high speed, add the hot butter in a thin, steady stream, then add the lemon juice and white wine vinegar. Season with kosher salt to taste and a generous pinch of sugar. Transfer the sauce to a microwave-safe cup or bowl.
Cut the English muffins in half and lightly toast them.
Carefully break an egg into a cup and slide it into the simmering water, or into the cups of an egg poacher. Repeat with the remaining eggs. Remove the skillet from the heat and cook until the yolks are medium-firm, 3 to 4 minutes.
Meanwhile, heat the Canadian bacon over high heat until slightly crisp, about 1 minute.
Place 2 English muffin halves on each of warmed plates.
Top each muffin half with a slice of Canadian bacon.
Using a slotted spoon, carefully lift out each egg and drain over the skillet. Blot the eggs lightly with a paper towel. Gently place 1 egg on top of each Canadian bacon slice.
If not keeping the hollandaise sauce warm in a double boiler, warm it in the microwave for about 10 seconds and pour generously on top of the eggs and around the English muffins. Season with pepper to taste and garnish with tarragon, if desired. Serve immediately.
Note: Heat the butter in a glass measuring cup in the microwave until it begins to boil. In order for the egg yolks to thicken the sauce, the butter must be very hot and the egg yolks, cream, and lemon juice must be at room temperature when you begin blending.Servings: 2