Can be prepared a day ahead and stored in the refrigerator. Allow it to come to room temperature before serving. Cook the rice and the peas in advance.
VINAIGRETTE: Whisk the mustard, salt, pepper and vinegar until dissolved. Drizzle in the oil while whisking. Toss the black-eyed peas and the rice with the vinaigrette until everything is nicely coated. Mix in the onion, garlic, carrot and chives or parsley. Bring to room temperature before serving.
Serve surrounded with radicchio or lettuce.