01 - In a large bowl, combine the diced tomatoes, sliced cucumber, and thinly sliced red onion.
02 - In a small bowl, whisk together olive oil, red wine vinegar, lemon juice, salt, and black pepper until emulsified.
03 - Pour the dressing over the vegetables and toss gently to coat.
04 - Sprinkle with chopped parsley and toss once more.
05 - Serve immediately, or refrigerate for up to 30 minutes to chill before serving.