How to Make It
In a large bowl, cover the black-eyed peas with cold water and let soak overnight. Drain and rinse the peas and transfer them to a large saucepan. Add 3 quarts of water and bring to a boil over high heat. Lower the heat to moderate and cook until tender, 30 to 35 minutes.
Drain the peas, rinse with cold water and drain again. Transfer the peas to a large bowl and add the onion, oil and vinegar. Toss the black-eyed peas with the parsley, season with salt and white pepper and serve.