1. Place the water and sugar into a small pot and set over medium to low heat.
2. Cook for 10–15 minutes, until sugar reaches a temperature of 338°F (170°C) on a candy thermometer. Do not stir the sugar, but watch it carefully. When it reaches the desired temperature, stir in the toasted nuts.
3. Quickly and carefully pour onto the prepared baking sheet and spread with the back of a spoon. Let the mixture harden, then break into small pieces.
4. Place in a food processor fitted with the S-blade and pulse until it reaches a fine consistency.