In a blender, combine egg yolks, mustard, and lemon juice. Puree until smooth. Place butter in a separate microwave safe container and microwave until melted. With the blender running, slowly pour hot butter in a steady stream. Sauce will thicken. Set aside in a warm place.
Heat a small skillet over medium high heat. Melt butter. Brown Canadian bacon in butter on each side and set aside.
Bring a large pot of salted water to a boil. Meanwhile, toast muffins
Stir vinegar into boiling water. Crack eggs into separate small bowls. Stir boiling water in a clockwise motion until a whirlpool forms. Gently slide egg from bowl into the boiling water, one at a time. Cover the pot and turn off the heat. Let poach 4 to 5 minutes. Use a slotted spoon to remove the poached eggs from the water.
Place 1/2 of a toasted English muffin onto a plate. Top with toasted Canadian bacon. Slide poached egg on top and drizzle with hollandaise sauce. Season with salt and pepper to taste and garnish with chopped parsley.