To make the hollandaise, place the egg yolks, lemon juice and one tablespoon of water in the bowl of a food processor. Turn on and mix for one minute. With the motor still running very slowly, trickle the warm melted butter through the funnel on the lid of the processor. The sauce with slowly start to thicken. When all the butter has been incorporated, scrape the side of the bowl and give one final pulse. Season with salt and a little white pepper. You should have a rich buttery sauce.
To poach the eggs bring two litres of water to the boil with the vinegar. Lower the heat so the water is not bubbling.
Break the eggs into separate ramekins or cups. Slide the eggs into the water and leave to poach 2-3 minutes. Alternatively, stir the water to form a vortex before you slide the first egg in and cook them one at a time. Cook for 2-3 minutes them remove and drain.
To serve, place a crumpet on a plate and top with a poached egg, spoon over some sauce and arrange the bacon on the side.