Toast the hazelnuts: Preheat the oven to 350°F. Spread hazelnuts on a baking sheet and toast for about 5 minutes, until fragrant. Transfer to a container with a tight-fitting lid (like Tupperware), seal, and shake vigorously to loosen the skins. Remove and discard skins; set nuts aside to cool.
Toast the pistachios: Place pistachios on the same baking sheet and toast for about 5 minutes, just until lightly golden and aromatic. Set aside to cool.
Toast the seeds: In a dry skillet over medium heat, toast the sesame seeds until light golden brown, stirring often. Transfer immediately to a bowl so they don’t continue to brown. In the same skillet, toast the coriander and cumin seeds, shaking the pan occasionally, until fragrant and the seeds begin to pop.
Grind and mix: Transfer the coriander and cumin to a food processor and pulse until finely ground. Pour into the bowl with sesame seeds. Add cooled hazelnuts and pistachios to the processor and pulse until the mixture resembles coarse breadcrumbs — you want texture, not nut butter. Add the nut mixture to the bowl with the ground spices, sprinkle in the salt, and stir well to combine.
Store: Transfer to an airtight container or zip-top bag and store in the freezer. Keeps well for several months.