1 English cucumber, washed and very thinly sliced
1/2 white or sweet onion, very thinly sliced into half moons
2 tablespoons rice or white wine vinegar
1-2 teaspoons sugar (adjust to taste)
Whisk together sugar and vinegar in a nonreactive bowl until sugar begins to dissolve. Add onions and cucumber and fold gently to combine. Serve right away or let stand for a few minutes to let the flavors marry.