Add jalapeno slices and lime juice to a cocktail shaker. Muddle the jalapeno slices to release their oils.
Add the tequila, Grand Marnier, brine, agave nectar and a handful of ice. Put on the top and shake vigorously for 15-30 seconds.
Run a lime slice around the rim of a martini glass. On a small plate, stir together sea salt and chili powder. Swirl the rim of the martini glass into the salt-chili powder mixture.
Strain the martini into the glass. Garnish with olive slices, a lime slice and additional jalapeno slices if desired.
When you're in the mood for a cocktail that's a bit different but still plenty refreshing, try this spicy Mexican martini.
Another amazing cocktail from this site. Love the light spiciness and the unique flavors. Was a hit at our house.