For egg poaching, bring enough water and the vinegar to the boil in a sufficiently large saucepan, reduce the heat a little and stir the water with a spoon handle until a small strudel is formed. Now let the beaten eggs slide carefully into this strudel - one at a time. The egg white envelops the egg yolk perfectly thanks to the gentle swirling movement. Leave the eggs in the water for 3 minutes, then remove them with a slotted spoon and place on a plate covered with kitchen paper.
In the meantime, toast the muffins or toasties and brush with butter. Heat a pan over medium heat and brown 4 slices of bacon or ham for 1 minute on each side, then transfer to large plates.
To serve, place 2 muffin or toastie halves on a warm plate, place a slice of ham on top of each other and place the poached eggs on top of the ham. Now pour the hollandaise sauce over the eggs, tablespoon at a time, garnish with chives and paprika powder.
For the hollandaise sauce, place a large bowl over a saucepan with gently simmering water, making sure that the bottom of the bowl does not touch the water.
Beat the egg yolks, lemon juice and mustard - if used - in the bowl. Pour the melted butter into the mixture in a thin stream, beating constantly until the whisk leaves traces in the sauce.
If it`s too thick, add a few drops of hot water. Season to taste with salt and cayenne pepper and, if necessary, a drop of Worcestershire sauce and keep the sauce warm over the water bath until you use it, stirring occasionally.