10 tablespoons unsalted butter (if using salted butter, omit the added salt)
3 egg yolks
1 tablespoon lemon juice
1/2 teaspoon salt
Dash of cayenne or tabasco
Heat a large skillet on medium low heat. Add the strips of bacon or the slices of Canadian bacon. Slowly fry, turning occasionally, until the bacon is browned on both sides, and if using strip bacon, much of the fat is rendered out (about 10 minutes). Remove the bacon from the pan, set on a paper towel to absorb the excess fat.
While the bacon is cooking, bring a large saucepan two-thirds-filled with water to a boil, then add the vinegar. Bring the water to a boil again, then lower the heat to a bare simmer.
To make blender hollandaise, melt 10 Tbsp unsalted butter. Put 3 egg yolks, a tablespoon of lemon juice, 1/2 teaspoon salt in a blender, blend on medium to medium high speed for 20-30 seconds, until eggs lighten in color.
Turn blender down to lowest setting, slowly drizzle in the hot melted butter, while continuing to blend. Taste for salt and acidity and add more salt or lemon juice to taste. Transfer it to a container you can use for pouring and set it on a warm (not hot) place on or near the stovetop.
To poach the eggs, crack an egg into a small bowl and slip it into the barely simmering water. Once it begins to solidify, you can slip in another egg, until you have all four cooking. Turn off the heat, cover the pan, and let sit for 4 minutes. (Remember which egg went in first, you’ll want to take it out first.) When it comes time to remove the eggs, gently lift out with a slotted spoon.
Note that the timing is a little variable on the eggs, depending on the size of your pan, how much water, how many eggs, and how runny you like them. You might have to experiment a little with your set-up to figure out what you need to do to get the eggs exactly the way you like them.
As soon as all the eggs are in the poaching water, begin toasting your English muffins. If you can’t get all the muffins toasted by the time the eggs are ready, gently remove the eggs from the poaching water and set in a bowl.
To assemble, butter one side of an English muffin. Top with two slices of bacon or 1 slice of Canadian bacon. Put a poached egg on top of the bacon, then pour some hollandaise over. Sprinkle some parsley over it all and serve.