1. In a large saucepan or Dutch oven, heat the oil over moderately low heat. Add the onion and the scallion bulbs and cook, stirring occasionally, until the onion is translucent, about 5 minutes. Add the collard greens, salt, black pepper, and cayenne and cook, stirring, until the greens wilt, about 1 minute.
2. Increase the heat to moderately high. Add the sausage, black-eyed peas, and rice and cook, stirring, for 30 seconds. Stir in the broth and bring to a simmer. Reduce the heat to low and cook, covered, until the rice is tender and all the liquid is absorbed, about 20 minutes. Remove from the heat and stir in the scallion tops.
Wine Recommendation: The robust flavors of Hoppin' John call for an equally assertive wine. Go for a brash, full-bodied red zinfandel from California. Its spicy blackberry richness is easily up to the task.
Notes: Collard greens braised to melting softness in the Southern style (slow-simmered with plenty of pork) are truly delicious, but the greens don't actually have to cook for hours. In twenty minutes they'll be just tender.