Cucumber Tuna Bites

Tuna with Apples and Celery served over thinly sliced Cucumber

1 can of tuna in olive oil
1/2 small apple diced
1 small stalk of celery with greens diced
1 tablespoon diced onion
1/2 teaspoon salt
1/2 teaspoon pepper
1/2 cucumber thinly sliced