Sift the flour and salt into a medium bowl and set aside. In the bottom of an electric mixer fitted with the paddle attachment, mix butter on medium-high speed until just fluffy, about 2 minutes. Slowly add the sugar and mix until smooth, then add the eggs one at a time. Mixing on low speed, add in the flour mixture until just combined. Wrap dough in plastic, and refrigerate until firm, about 2 hours.
Preheat oven to 350°F (177°C). Line baking sheets with parchment paper.
On a lightly floured surface, roll out dough to about ⅛ inch thick. With a glass or round cookie cutter, cut into 1½-inch rounds. Use a spatula to transfer the rounds to baking sheets, spacing 1 inch apart.
Bake cookies for about 12 minutes, rotating halfway through. Cookies should be golden on the bottoms and the edges. Transfer to wire racks and let cool completely.
Topping
In a food processor or blender, grind the pistachios until crumbly and chunky. You don't want whole pistachios or a fine crumble, but somewhere in between. Transfer to a small bowl and set aside.
Melt the chocolate in a double-boiler or in 20-second increments in the microwave on low heat. Do not allow to burn. Stir.
Dip cookies ⅓-way into the chocolate, then gently roll the top in the pistachio chunks. Place on a baking sheet lined with parchment paper. Allow to set in the fridge for 15 minutes. Store in an airtight container.