In a large stockpot, add black beans, green pepper and water. Angela measures to make sure water is 1 inch above the beans. Allow the beans to soak overnight.
The following day, bring the beans to boil in the soaking liquid and then reduce to simmer for 1 hour. At that point, remove foam and bring back up to a boil.
While the beans are simmering, make the sofrito. In a large stockpot, add 1 cup of oil and add chopped onion and green peppers. Sauté over medium heat until onions are translucent and peppers are soft but not browned, about 20 minutes. Add pureed pimentos and simmer for five more minutes. Pour the mixture into the food processor a puree until smooth.
After an hour and 30 minutes, carefully remove the pepper from the beans and add the ground sofrito and simmer for one hour. (Cook’s Note: before adding the sofrito, make sure beans are soft, if not, cook until tender) Then, add 1/3 cup of oil and mix to combine. In 15 minutes, add another 1/3 cup and then after an additional 15 minutes, add the last 1/3 cup.
At this point, you can add the kosher salt, pepper and vinegar. Mix to combine. Allow another ½ hour of cooking.
