In a food processor, combine the shelled pistachios and ¼ cup sugar to create a paste. This will take a while, around 5 minutes.
In a small bowl, whisk together the egg yolks and ¼ cup sugar.
In a pot over medium heat, combine the whole milk, 1 cup heavy cream, and ¼ cup sugar. Stir continuously until it reaches around 185℉ or for about 4-5 minutes.
Temper the egg yolks. To do this, ladle a small amount of the heavy cream + milk mixture into your bowl with the egg yolks + sugar while whisking constantly.
Add your tempered egg yolks to the pot with the heavy cream + milk and stir constantly for 5-10 minutes, until it thickens.
Remove from heat. Add 1 cup of heavy cream, vanilla extract, almond extract, sea salt, and pistachio paste. Stir well until it is all completely combined.
Chill overnight.
Make your pistachio ice cream according to the directions on your ice cream machine.