In a cocktail shaker, muddle the lime juice, agave, and arugula, then add the gin and ice. Shake, then strain into a rocks glass filled with ice and garnish with wild radish flowers or micro arugula.
In a bowl, combine 1 cup agave nectar and 1 cup water. Stir until the agave has dissolved and the mixture is well combined. The agave syrup will keep in an airtight container in the refrigerator for up to 6 months.