Wash cucumber, tomato, and red onion under cold water. Finely dice cucumber and tomato. Soak red onion in cold water for about 10 minutes, then chop finely.

In a large mixing bowl, combine the diced cucumber, tomato, and red onion with freshly chopped cilantro. Gently mix with a wooden spoon.

Drizzle with olive oil and lime juice, sprinkle salt and pepper to taste, and mix gently.

Allow the salad to sit for 10-15 minutes at room temperature to let flavors meld.

Serve at room temperature or chill slightly in the refrigerator.