Make a Bain Marie by placing a large metal bowl over a smaller pan of simmering water, ensuring the bottom of the bowl does not touch the water.
Melt the butter gently in a separate small pan.
Place the egg yolks, a pinch of salt and the vinegar into the bowl and start whisking rapidly, don’t stop until they become lighter in colour and fluffy in texture.
Very slowly start drizzling in the butter a little at a time, incorporating each addition with the whisk before adding any more. If the sauce becomes too thick or looks like its splitting, you can remove from the heat and whisk in a little of the water from the Bain Marie
Once all the butter is in, stir in the paprika, lemon juice, sriracha, Worcestershire 2 tsp of freshly grated horseradish and check for seasoning.
Serve with poached eggs on toast smeared with English mustard and topped with a grating of fresh horseradish.
