Prepare the glass: Pour about ¼ cup of the kosher salt onto a small plate. Rub a lime wedge around the rim of a rocks glass, then dip the rim into the salt until evenly coated. Set aside.
Build the margarita: Fill a cocktail shaker halfway with ice. Pour in the 3 ounces tequila first, followed by the 1 ounce orange liqueur, 1 ounce agave syrup, passion fruit pulp, and fresh lime juice from 2 limes.
Shake well: Cover the shaker and shake vigorously for 15–20 seconds, until the outside of the shaker is cold and slightly frosted.
Serve: Fill the prepared glass with ice and strain (or pour) the margarita into the glass.
Garnish and enjoy: Garnish with the reserved passion fruit half and serve immediately. Cheers!