Put sansho peppercorns and cheap vodka in a sealed bottle and let them infuse for at least a week. Gently shake or swirl the bottle every day and store away from intense light or heat.
To make the cocktail, pour all ingredients into a cocktail shaker with ice. Shake well and strain into martini or coupe glasses, garnish with lemon slices.
More About This Recipe
Depending on how long your sansho vodka has been infusing and how strong a sansho flavor you like, you can vary the ratio of infused to plain vodka in the cocktail. Optional: Add a few drops of yellow food coloring for visual appeal.