I am currently on the Island of Mull in the Hebrides. On the nearby island of Colonsay evidence suggests that local residents were consuming large amounts of the nut in 7000BC.
The Hebrides can often feel very far from civilisation so the fact that people living here enjoyed this tasty snack several millennia before the Babylonian Empire existed blows my mind just a little bit.
Anyway, while we Hebrideans might have harvested the nut from our trees back then, the undisputed champion of hazelnut production today is Turkey, which produced 660,000 tonnes of the nut in 2012.
Drizzle them in a little oil, sprinkle over some salt and maybe some pepper and/or herbs, then roast them in a pre-heated oven for about 10-15 minutes, depending on the heat. Essentially you want to toast them, not burn them. If they seem slightly soft when you remove them from the oven they will probably harden to a nice crunchy texture as they cool.
Alternatively, you could go one step further and make something from across the Mediterranean from Turkey: Egyptian Duqqah.
Dip the bread in the oil then coat it in the duqqah with one hand while you sip your martini with the other.
This is simple and delicious. You can also mix the duqqah with other ingredients such as pepper, ground chickpeas and other ground nuts if you like.