Preheat oven to 350 degrees F (176 C). Line a couple of cookie sheets with parchment paper.
Beat butter, shortening and both sugars with an electric mixer until creamy. Add egg and vanilla and beat for about 30 seconds. Scrape sides of bowl and beat in salt and baking soda. Add flour and stir until it is almost mixed in, then stir in macadamia nuts and white chocolate.
Drop dough about 3 inches apart (these spread quite a bit) by tablespoonfuls onto cookie sheets. Bake for 12-14 minute or until edges are golden brown. Cool on cookie sheets for about 5 minutes, then transfer to wire racks.