Preheat the oven to 300°F (150°C) and line two baking sheets with parchment paper.

In a stand mixer, beat together the butter, granulated sugar, and brown sugar until pale and fluffy. Add the egg and vanilla extract, mixing until incorporated.

In a medium bowl, whisk together the flour, baking soda, and salt. Add to the butter mixture and mix on low speed until just combined. Fold in the chocolate chips and pistachios.

Scoop dough into tablespoon-sized portions and place on baking sheets, leaving space between each. Lightly sprinkle with sea salt and refrigerate for 15 minutes.

Bake for 14-16 minutes, depending on desired doneness. Let cool on sheets for 5 minutes before transferring to a wire rack to cool completely.