In saucepan over medium heat, cook sugar with 1/4 cup water to dissolve; remove from heat. Reserve 1 jalapeno slice; stir remaining slices into syrup. Let sit 5 minutes, then strain and let cool. Pour salt onto plate. Salt rim of rocks glass. In shaker, combine tequila, triple sec, lime juice, 1 tbsp. jalapeno syrup and ice. Shake and strain into ice-filled glass. Garnish with reserved jalapeno slice.
