In a very large bowl, combine the rinsed and drained black-eyed peas, black beans, corn, diced red onion, green bell pepper, diced tomatoes, and minced jalapeño (if using).

In a separate small bowl, prepare the vinaigrette. Whisk together the olive oil, red wine vinegar, cumin, dried oregano, salt, pepper, and minced garlic until well emulsified.

Pour the prepared vinaigrette evenly over the bean and vegetable mixture.

Gently fold the ingredients together until everything is thoroughly coated with the dressing. Avoid crushing the beans.

Cover the bowl tightly and refrigerate for at least 4 hours, or preferably overnight, to allow the flavors to meld together. This step is crucial for an authentic taste.

Taste and adjust seasonings (salt/pepper/vinegar) before serving. Serve chilled with tortilla chips, crackers, or fresh vegetables.