Line a baking sheet with parchment or wax paper and scatter the pistachios on the baking sheet. Using a double boiler on the stove or a glass bowl in the microwave, heat the chocolate chips until just melted. Stir until smooth. Very carefully, pour the melted chocolate over the pistachios until covered and top with the crystallized candied ginger and sprinkle on some sea salt. Refrigerate for at least 30 minutes, or until firm enough to cut or break apart.