Ahead of time preheat your oven to 375. Also make sure your butter is soft. Combine butter, shortening, white sugar, and brown sugar into large mixing bowl and mix on medium speed until creamed. Then add the vanilla and the egg. In a separate bowl put the flour, salt, and baking soda together and gently mix until combined. Now, add a little flour at a time to your wet mixture and beat with the mixer on low to medium speed until the flour is combined. Keep doing this until all the flour is incorporated and mixed into the butter-sugar mixture. Next you add your chocolate chips and mix in with a wooden spoon. Now get a regualar table spoon and put rounded scoops of the dough onto a greased cookie sheet. Bake for 9 minutes or until golden brown.