Combine the diced tomatoes, cucumbers, and onion in a large bowl. Stir to combine.
Top with the parsley and mint and stir to combine.
In a small bowl, whisk together the olive oil, lemon juice, sumac, sea salt, and black pepper to combine.
Pour the dressing over the salad and toss to combine.
Serve immediately or allow to rest for 30 minutes at room temperature for the flavors to come together.
