Peel and chop the cucumber and jalapeno.

In a blender, combine the chopped cucumber and jalapeno with a splash of water and blend until smooth.

Strain the blended mixture through a fine mesh strainer into a bowl or pitcher.

In a shaker, combine the cucumber-jalapeno juice with tequila, lime juice, and agave syrup.

Add ice to the shaker and shake vigorously for about 15 seconds.

Rim the glasses with salt if desired.

Fill the prepared glasses with ice and strain the margarita mixture over the ice.

Garnish with a lime slice or cucumber ribbon.