Melt unsalted butter in a small saucepan over medium heat. For a thinner sauce, use unsalted butter. Try not to let the butter boil, as this allows some of the moisture to evaporate.
Combine egg yolks, fresh lemon juice, Kosher salt, Dijon mustard, and a pinch of Cayenne pepper in a blender. Blend until well mixed.
Pan frying them in a little butter, cut side down, in a skillet over medium heat until crispy. If you use a toaster oven, spread each half.
Fill a medium saucepan with at least 3 inches of water, then add white vinegar. Set over medium heat and bring to a gentle simmer, or just lower. You don’t want the water to boil. Crack each egg into a small ramekin or bowl. When the water is just below a simmer, carefully drop one egg at a time.
Place English muffin halves on each plate. Top each with smoked salmon. Place a poached egg on top of each half, then spoon on as much of the hollandaise sauce as you like. Garnish with capers and fresh dill. Enjoy!