In a medium saucepan over medium-low heat, melt the butter until it boils. Stir constantly until the butter browns, about 5 minutes. It will turn a deep amber color. Remove from heat and let it cool for 20-30 minutes.
Preheat the oven to 350°F. Line a baking sheet with parchment paper.
Once the butter has cooled, add it to the bowl of a stand mixer with the brown sugar and granulated sugar. Mix on medium speed for 1 minute. Then add honey, egg, vanilla, sea salt, and baking soda. Mix for another minute until combined.
Reduce mixer speed to low and add flour, mixing until just combined. Stir in pistachios and white chocolate chips until evenly mixed.
Use a medium cookie scoop (about 2 tablespoons) to drop dough onto the prepared baking sheet about 2 inches apart. Bake for 8 minutes or until edges are lightly golden. Be careful not to over-bake!
Let the cookies cool on the baking sheet for 3-4 minutes, then transfer to a wire rack to cool completely.
Sprinkle with flaked sea salt if desired for an extra touch of flavor.
Notes
For extra flavor, you can toast the pistachios before adding them to the cookie dough.