Mix equal parts salt and chili powder on a small plate for the rim.
Run a lime wedge around the rim of the glass. Dip it in the salt mixture.
Put cucumber and jalapeño slices in the shaker. Muddle gently to release flavors.
Add tequila, lime juice, and triple sec to the shaker.
Fill the shaker with ice. Shake for 15-20 seconds.
Double strain into the rimmed glass filled with fresh ice.
Garnish with a cucumber slice and jalapeño ring.
Notes
Change the spice level by using more or less jalapeño, or by adjusting muddling time.Remove all seeds and white membranes from the jalapeño for less heat.Fresh ingredients improve the flavor. Use ripe cucumbers and fresh limes instead of bottled juice.Store the drink in a pitcher without ice for up to 4 hours if making ahead.Add more chili powder or use tajin seasoning for a spicier rim.