Soak the black-eyed peas in plenty of water for at least 8 hours. Rub them between your hands to remove the skins, then rinse well.
Blend the peeled beans, bell pepper, chili, onion, water, oil, curry powder, salt, and white pepper until very smooth. Add a splash more water if needed for a thick, pourable batter.
Steam:
Grease six heatproof ramekins and divide the batter between them, leaving about 1 cm of space at the top. Cover each tightly with foil.
Set the ramekins in a steamer over simmering water. Cover and steam for 45 to 50 minutes, until the centers are firm and a skewer comes out clean.
Sauce and Serve:
For the sauce, warm the oil in a skillet. Cook the onion for 3 minutes, add the tomatoes, and simmer for 10 minutes until thick.
Rest the moi moi for 5 minutes, unmold, and serve with the warm tomato-pepper sauce.
Notes
Do not let the steamer run dry.
The batter should be smooth enough to pour but not watery.