1. Preheat oven to 350F
3. In the stand mixer bowl add butter, sugar, salt and flour.
5. Attach the paddle attachment . Turn on the mixer on medium speed and mix for 1 to 2 minutes until forming a soft and smooth dough . You can use it right the way or leave it to rest for at least one hour.
7. Divide dough into small balls ( walnut size or smaller ) . Put a piece of pistachio right in the center of the ball and press lightly. Arrange balls in a cookie sheet by making a 1 inch distant between them .
8. Bake on the middle rack ogf the oven for 8 to 10 minutes. It is important that the color of the cookies do not change, and remains white during baking ( be careful not to over bake ) .
9. Bring Cookies out of the oven and transfer cookies to a wire rack to let cool . Store in a tight cover container