Preheat your oven to 350°F (175°C). This ensures that the cookies bake evenly.

In a mixing bowl, cream together the softened butter, brown sugar, and granulated sugar using an electric mixer on medium speed until the mixture is light and fluffy, about 2-3 minutes. This process incorporates air into the butter, making the cookies tender.

Add the egg and vanilla extract to the butter mixture, and mix until fully combined.

In a separate bowl, whisk together the sifted all-purpose flour, baking soda, and salt. This ensures that the baking soda is evenly distributed throughout the flour.

Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined. Be careful not to overmix, as this can lead to tough cookies.

Fold in the dark chocolate chunks and chopped salted pistachios using a spatula, ensuring they are evenly distributed throughout the dough.

Line a baking sheet with parchment paper to prevent the cookies from sticking.

Using a cookie scoop, drop rounded tablespoons of dough onto the prepared baking sheet, leaving about 2 inches of space between each cookie to allow for spreading.

Sprinkle a small pinch of sea salt on top of each cookie dough ball before baking. This enhances the flavor and gives a nice salty contrast to the sweetness.

Bake in the preheated oven for 10-12 minutes, or until the edges are lightly golden and the centers are still soft. The cookies will continue to cook slightly after being removed from the oven.

Allow the cookies to cool on the baking sheet for 5 minutes before transferring them to a cooling rack to cool completely.