Place the diced cucumber, peppers, and onion in a bowl. Add the chopped parsley and the diced tomatoes with their juices. Using your hands or two wooden spoons, gently toss the ingredients to combine. Drizzle the olive oil evenly over the top, then gently toss to coat. Scatter the dill over the top and sprinkle with sea salt. Toss gently but thoroughly to combine. Taste for seasonings. Serve at room temperature.