Place water in a large heavy pot and add peas, salt, black pepper, cumin seeds, chili powder, cayenne pepper and 1 diced onion. Bring to a boil over high heat, cover, reduce to low heat and slow simmer for 3 to 4 hours until peas are soft but not mushy. After 2 hours, check every 30 minutes for texture. When peas are cooked, set aside to cool.

While peas are cooking, combine remaining onion and jalapeno peppers in a small mixing bowl. Add enough ume vinegar to barely cover onion mixture. Cover bowl and set aside to pickle for at least 1 hour. Place in refrigerature until peas are cooked. Once peas are cooled, drain the pickled onion mixture of excess liquid, keeping the ume liquid in case more salt flavor is needed for final dish.  Add onion mixture and bell peppers to cooled peas and thoroughly mix. Add cilantro and season with remaining ume and black pepper to taste. Allow flavors to meld for at least 1 hour before serving. May be refrigerated for up to 3 days.