High quality Extra Virgin olive oil is nothing else than the  extraction of its juice by mechanical means , no difference from producing any natural juice.

What is the recipe to make the best  Extra Virgin olive oil?

The same  that is needed to make any best natural fruit juice: Have the best fruit, get your juice and you're done.

Why is it a belief?

Because for making the best and healthiest olive juice I must sacrifice production, carefully hand picking  fruit by fruit  in its exact maturity degree -when the fruit is perfect and not when it is ripe that would yield more oil but not so high quality-.  Everything must be natural without additives or preservatives of any kind.