Place black-eyed peas into a large container and cover with several inches of cool water; let stand for 8 hours to overnight. Drain and rinse peas.

Combine peas, onion, tomato sauce, olive oil, cilantro, garlic, salt, cumin, paprika, ginger, and cayenne pepper in a large stockpot; pour water over pea mixture. Bring to a boil. Reduce heat to low, cover the pot, and simmer, stirring occasionally and adding more water if sauce gets too thick, until peas are tender, about 1 hour 30 minutes.