Gelato is denser than ice cream, thanks in part to the larger amount of milk versus cream and the slower rate at which it's typically churned. The slower churning pace incorporates less air, yielding a texture that's less fluffy, and the lower percentage of fat makes the flavors taste more intense. "Stracciatella was always my go-to flavor," says chef and ice cream maker Fany Gerson. "In this recipe, I love putting that classic Italian flavor with another traditional Italian ingredient: pistachio. It just works." When the melted chocolate is added at the end of churning, it hardens right away, creating crunchy bits throughout the mixture for a fun take on two classic Italian flavors.

Stir together milk, cream, and zest in a medium saucepan. Cook over medium-low, undisturbed, just until steaming, making sure mixture doesn't bubble, about 5 minutes. Remove from heat; cover and let infuse about 10 minutes. 

Meanwhile, whisk together egg yolks, sugar, and salt in a medium bowl until smooth. Set aside until ready to use.

Pour infused milk mixture through a fine wire-mesh strainer into a separate bowl; discard solids. Gradually whisk infused milk into yolk mixture. Wipe saucepan clean.

Pour milk-yolk mixture back into cleaned saucepan. Cook over medium-low, stirring constantly using a wooden spoon, until mixture is thick enough to coat the back of a spoon, 6 to 10 minutes, making sure mixture doesn't bubble. Remove from heat. Pour through a fine wire-mesh strainer into a medium bowl; discard solids. Whisk in pistachio paste. Place medium bowl in a large bowl filled with ice water, and let stand, stirring occasionally, until mixture reaches room temperature, about 8 minutes. Transfer mixture to a resealable container; seal and chill at least 1 hour or, preferably, 12 hours. 

Pour chilled pistachio mixture into frozen freezer bowl of an ice cream maker; proceed according to manufacturer's instructions for soft-serve consistency.

Meanwhile, microwave chocolate and oil in a small microwavable bowl on high until just melted, about 1 minute, stopping to stir every 15 seconds. Let cool about 5 minutes. Set aside until ready to use. 

When gelato reaches soft-serve consistency and with maker running, gradually stream in chocolate until well combined, about 1 minute. Transfer to an 8- x 4-inch loaf pan; cover with plastic wrap pressed directly on gelato surface. Freeze until firm, about 4 hours. Store gelato in an airtight container in freezer up to 1 week. To serve, transfer gelato to refrigerator until temperature reaches 16°F or gelato is easily scoopable, about 40 minutes.

Find pistachio paste online at fiddymentfarms.com.