Preheat oven to 350 degrees (F).
In a medium bowl sift together the flour, salt and baking soda. Set aside.
In a large bowl (or stand mixer), cream together butter, shortening and sugars. Add in the eggs one at a time and mix until combined. Add the vanilla.
About 1 cup at a time, add in the flour mixture into the wet ingredients. Mix until just combined.
If using a stand mixer, remove bowl and add it the macadamia nuts and white chocolate chips - making sure to mix by hand. Do not over mix.
Place in the fridge for 5 minutes, especially if you used a stand mixer. The stand mixer may heat up and melt the butter/shortening slightly and this will affect how the cookies spread.
Scoop the dough into 1 tablespoon balls and keep about 1.5 inches apart on an ungreased cookie sheet.
Bake for 8-10 minutes, depending on the heat of your oven. You don't want the cookies to overly brown and they should maintain a slightly soft texture in the center.
Remove from baking sheet to a wire rack after about 2 minutes out of the oven so the bottoms don't brown too much. Allow to cool and store for up to a week in a food safe container.