Preheat oven to 350F
Microwave the butter for 40 seconds until just melted but not hot.
In a large bowl, mix the melted butter with the sugars until well combined
Stir in the vanilla and egg until incorporated
Add in the flour, baking soda, and salt
Mix dough until just combined. Dough should be soft and a little sticky, but not overly sticky.
Fold in the chocolate chips and pistachios.
Scoop out 1.5 tbs of dough and place 2 inches apart on a prepared baking sheet with parchment paper
Bake for 7-10 minutes or until the cookies are set. They will be puffy and appear underbaked in the middle.