Wash the vegetables. In a bowl, squeeze the limes, add salt and oregano. Finely dice the vegetables, mix everything together, and let it sit for about 5 minutes before enjoying.

For a more elaborate version, add finely chopped cilantro and diced avocado. It's even tastier if you add chopped cucumber, radishes, and raw broccoli.

My mother-in-law sometimes roasts the onion, peppers, and tomatoes before chopping them, which is another option (I don't prefer it, though).