Lay nuts out on a baking tray and have another baking tray ready for when they come out the oven. Place in the oven for 5 minutes.
Remove tray and move nuts around. (This will avoid hot spots). Place back in the oven for another 3 minutes. Check again - the nuts should have darkened slightly and smell 'nutty'. If you think they can take another couple of minutes without burning then do so but watch carefully.
Remove from oven and transfer to the cool baking sheet. If your nuts still had the skin on then now is the time to remove them. Place the nuts in a plastic bag and roll your hand over the bag vigorously until the skins peel off.
Place the cleaned and roasted nuts in a bowl next to the stove top.
To make the caramel
Line a baking tray with baking parchment and leave next to the stove top.
Place the sugar and water in a pan. Stir until all the sugar is coated with the water. Turn the heat on to medium and stir until the sugar melts. Do not let the mixture come to the boil before the sugar has melted.
Once the sugar has melted, leave the mixture to bubble away on it's own. Every now and again swirl the pot to redistribute the mixture. If you stir with a spoon the mixture will crystallise and be ruined. Eventually the mixture will start to colour. As soon as it reaches a golden caramel colour, remove from the heat and tip the nuts in. (Mine takes about 6 minutes to reach this stage).
Working quickly, pour the mixture out on to your baking tray and spread out thinly using a wooden spoon. Leave to set.
Break into shards using a rolling pin and use as is or blitz into smaller pieces using a food processor.
Do not be tempted to touch the caramel with your fingers - it is HOT, HOT, HOT.