Preheat the oven to 325F and line a baking tray with parchment paper.
Add all the Sumac coating ingredients and sweetener into a small bowl and combine them evenly.
Gather all the nuts into a larger bowl and mix them up.
In another small bowl, whisk the egg white until it is frothy and no liquid remains.
Add the egg white froth to the nuts to coat them evenly, then add the sumac mixture and incorporate everything, ensuring all the nuts are covered in the sumac mix. There should not be any liquid in the bottom of the bowl.
Spread the nuts onto the baking tray and bake for 8-10 minutes.
Switch the oven off and let the nuts sit for another 2 minutes. They should be brown but I like to leave them in the oven a little longer while it is still warm.
Remove the tray from the oven and let the nuts cool until they crisp up. Sprinkle extra sumac over the cooled nuts and toss them around until coated with the spice.
Serve or store them in an airtight container (once cooled completely) and leave them on the counter for up to 2 weeks.