To make the hollandaise, gently melt the butter and vinegar together in a pan.
Place the egg yolks in a liquidiser along with the water and pepper.
Blitz the egg yolks and water together for 15 seconds.
Bring the butter and vinegar to the boil.
Turn on the liquidiser and add the boiling butter and vinegar mix to the egg yolk mixture in a thin stream. It will thicken considerably.
Once all in, turn off and pour into a warm bowl or pan, cover with film and leave to set for 5 minutes, stirring occasionally.
Taste the sauce and adjust the seasoning, adding a squeeze of lemon juice, keep warm.
Bring a pan of water to the boil.
Crack the 4 eggs into the water, turn down the heat and poach for 3-4 minutes, do not overcook.
Meanwhile, place the 4 halves of muffin on 4 plates.
Top with a slice of ham and a few baby leaf salad leaves.
Place the eggs on top and spoon over the hollandaise.