Slice the muffins in half to give you two rounds from each and get broiler/grill ready to toast, if using. Heat a pot of water for poaching your eggs and separate your slices of smoked salmon.
First, start on the hollandaise sauce - put the two separated egg yolks into a blender container along with the cayenne pepper, mustard and lemon juice and blend until smooth.
Meanwhile, poach your two whole eggs and the leftover whites in slightly salted water until the whites are translucent and the yolks are still slightly soft.
As the eggs are almost ready, toast your muffins and melt the butter.
Add the melted butter in a steady pour to the egg yolk mixture, with the blender running the whole time so that it is properly combined.
Serve it all up - on each plate place the two halves of a muffin with a slice of smoked salmon on top, then a whole egg on one side, the extra white on the other. Drizzle the hollandaise sauce over the top.
Note - you need to do a few things at once to save things becoming cold so read through before starting.