In a small saucepan, bring the Triple Sec and Tequila to a simmer. Reduce to 2 tablespoons. Transfer the mixture to a small bowl and refrigerate until well chilled.
In a medium bowl, whisk together the zest, juice, and sugar. Add the heavy cream, concentrate, salt, chilled reduction, and whisk to combine. Pour the mixture into an ice cream maker and churn according to the manufacturer's directions. (The mixture will be just thick, not solid.) Transfer the mixture to a freezer-safe container and freeze until firm, several hours, and preferably overnight. (Ice cream will be of soft-serve consistency.)
Scoop into bowls or, for effect, small dishes rimmed with lime juice and kosher salt. Enjoy!