Preheat the grill to its highest setting.
Poach the eggs in a pan of boiling water.
When the pancetta is cooked, keep it on a warm plate while you lightly toast the split muffins on both sides.
Now butter the muffins and place them on the baking tray, then top each half with two slices of pancetta.
Put a poached egg on top of each muffin half and then spoon over the hollandaise, covering the egg (there should be a little over 1 tablespoon of sauce for each egg).
Now flash the Eggs Benedict under the grill for just 25-30 seconds, as close to the heat as possible, but do not take your eyes off them - they need to be tinged golden and no more. This should just glaze the surface of the hollandaise. Serve straight away on hot plates.