Drop a tablespoon of almond butter into the food processor, and pulse until it's mixed in. Now drizzle cooled sugar syrup or corn syrup into the food processor and pulse - just a little bit at a time. Only add enough syrup to get a good paste texture that holds together well. I probably only drizzled in about a tablespoon.
Now ball up the pistachio paste, and you can just store it in the fridge for a week or two in a plastic bag or container.