Here, a coarse sea salt like fleur de sel or sel gris plays a few important roles: It tempers and cuts the richness of the nuts and butter, it adds a concentrated crunch—and it makes the brittle look divine. Break this vibrant green pistachio brittle on top of ice cream or crumble it over rice pudding. Or, do what we do, and eat it straight off the baking sheet.
- Nonstick vegetable oil spray
- 1 cup unsalted, shelled raw natural pistachios, very coarsely chopped
- 1 tablespoon unsalted butter
- Coarse gray sea salt (such as fleur de sel or sel gris)
Line a rimmed baking sheet with parchment paper; spray with nonstick spray and set aside. Whisk sugar, corn syrup, and 3 tablespoons water in a medium saucepan. Stir over medium heat until sugar dissolves. Fit saucepan with candy thermometer, bring mixture to a boil, and cook until thermometer registers 290°, 3-4 minutes.
Using a heatproof spatula, stir in pistachios, butter, and kosher salt (syrup will seize initially, but will melt as it heats back up). Continue to cook syrup, stirring often, until thermometer registers 300° and pistachios are golden brown, 3-4 minutes. Caramel should be pale brown (it will darken slightly as it cools). Sprinkle baking soda over and stir quickly to blend caramel thoroughly (mixture will bubble vigorously).
Immediately pour caramel onto pre- pared baking sheet and, using a heat- proof spatula, quickly spread out as thin as possible. Sprinkle sea salt over and let caramel cool completely. Break brittle into pieces. DO AHEAD: Brittle can be made 1 week ahead. Store airtight between sheets of parchment paper (to prevent sticking) at room temperature.