In a deep bowl, put the hazelnuts with enough boiling water to cover them, & let them soak for 1 hour, then drain them.
In a blender bowl, put the nuts along with the bread, garlic & 1 teaspoon of water, then blend until smooth, before drizzling the oilve oil into this mixture with the motor running.
When oil is completely absorbed, add lemon juice & salt to taste. NOTE: If patience is one of your virtues AND you have energy to spare, you could do this grinding & blending in a large mortar with a pestle!
Taste & adjust the seasoning, if desired, then transfer to a serving bowl & serve at room temperature.