Mix 1 1/2 teaspoons salt, the sugar, chile powder, cumin, coriander, lime zest and garlic in a small bowl; set aside.
Preheat the oven to 350 degrees F and brush a rimmed baking sheet lightly with vegetable oil. Whisk the egg white in a large bowl until frothy. Add the cashews, pecans and mini pretzels. Sprinkle with the prepared spice blend and toss to coat. Spread the nut mixture evenly on the baking sheet and bake, stirring occasionally, until golden brown, 15 to 20 minutes; let cool on the baking sheet.