Dice the tomatoes and cucumber (if using) into bite-sized pieces.
Thinly slice the onion and hot green pepper (if using).
In a large mixing bowl, combine the diced tomatoes, sliced onion, diced cucumber (if using), minced garlic (if using), and sliced hot green pepper (if using).
Drizzle the vegetable oil or olive oil over the salad.
Add the vinegar and toss to combine.
Season the salad with salt and freshly ground black pepper to taste.
Add the chopped fresh cilantro or parsley and toss gently to combine.
Enjoy your meal!