For the hollandaise sauce

1. Start with yolks and lemon juice.  In a small, heavy saucepan whisk the egg yolks and 1 tablespoon lemon juice together until combined.
2. Add butter. Set the pan over very low heat and add 1 (4 tablespoon) portion of butter.
3. Cook gently. Cook the mixture, whisking constantly and allowing the butter to slowly melt and incorporate into the egg mixture. Remove the pan from the heat occasionally if the pan gets too hot and eggs begin to curdle. When the first portion of butter is incorporated, add the second portion. Continue cooking and whisking until the butter is melted and the mixture thickens. Taste and add more lemon juice to taste.
4. Set aside. Keep sauce warm while preparing the eggs and crab (see Notes).

For serving

1. Toast muffins. Lightly toast the English muffins, then keep warm in the oven.
2. Warm crab. Meanwhile, in a small sauté pan, melt the butter over medium heat. Add the crab and lemon juice. Heat the crab gently until warmed through. Set aside.
3. Poach eggs. For the eggs, crack the eggs into 4 small ramekins or sauce dishes. In a 12-inch straight-sided skillet or large saucepan, bring 3 inches of water to a simmer. Turn down the heat so that no more bubbles form on the surface. Carefully slide the eggs into the water, evenly spreading the eggs around the pan so they don’t touch each other. Cook eggs, undisturbed, until white is just set and yolk is still runny, 3 to 4 minutes. Use a rubber spatula to gently release eggs from the bottom of pan, if necessary. Using a slotted spoon, remove eggs from water and set them on a paper towel lined plate.
4. Plate and serve. Place muffin slices on plates. Top each muffin slice with a quarter of the crab mixture, a poached egg and some of the sauce. Season with salt and pepper to taste and garnish with chopped parsley if desired. Serve immediately.