Preheat the oven to 350°F (180°C).
Place the hazelnuts on a parchment lined baking tray in a single layer and roast for 12 minutes.
Allow to cool for a few minutes and then roll them with your hands to remove the skins. The skins will come off easily, any parts that don't, just leave them on.
Add the roasted hazelnuts to the food processor and process into a hazelnut butter. It will start off crumbly and then will gradually form into sticky clumps and then finally will go into a smooth butter. If it sticks to the sides too much, then stop the machine and scrape down the sides and then continue.
Add the salt and process in. Taste test and add more salt if desired.
Break up the chocolate and place into a microwave safe dish. Microwave in 30-second intervals, bringing it out to stir every 30-seconds, until completely melted.
Add the melted chocolate to the hazelnut butter and process it in.
At this point you should have a nutella that is still a little textured, as food processors often don't get things completely smooth. If this is the case, then transfer to your blender jug for the final step which is blending it completely smooth in the blender.
Transfer to a container and let it gradually thicken at room temperature until it reaches a consistency similar to smooth peanut butter.
Keep it stored at room temperature (covered) and enjoy over the next couple of weeks.