Grind 1/2 teaspoon each caraway and coriander seeds in a spice grinder. Whisk 2 egg whites to soft peaks; fold in the spices, 2 teaspoons kosher salt, 6 chopped dried arbol chiles, 1/3 cup sugar, 1/4 teaspoon orange zest, 3 cups mixed nuts and 3 tablespoons diced butter. Spread on a baking sheet; bake at 325 degrees F, stirring occasionally, 45 to 50 minutes. Let cool. Crumble the chiles for extra heat.