Heat the olive oil in a large pot over medium heat.
When the oil is hot, but not smoking add the onions, carrots and celery. Cook the vegetables for 5 minutes, stirring frequently.
Add the garlic, tomato paste, salt, dried oregano, cumin and black pepper to the pot. Cook for 1 minute while stirring.
Add the pork shanks, chicken broth and the water to the pot and stir well, while gently scraping any bits off the bottom of the pot.
Raise the heat to high and bring the liquid to a boil. Once it’s boiling, lower the heat to medium and cover the pot. Cook the broth with the ham shanks for 30 minutes.
Remove the pork shanks from the pot. Set them on a cutting board and allow them to cool a bit.
Lower the heat on the broth to low, cover the pot and continue gently cooking the broth.
When the pork shanks are cool enough to handle, take the meat off the bone and chop it into small pieces. Discard the bone and any fatty pieces.
Raise the heat to medium and add the chickpeas and the chopped pork to the pot, stir well.
Cover and cook the soup for 15-20 minutes, stirring occasionally. Make sure the broth comes to a simmer, raise the heat if needed.
Add the potatoes to the chickpea soup.
Lower the heat to medium-low, cover the pot and cook the soup for 25-30 minutes, until the potatoes are tender and the chickpeas are soft and creamy in the center. Stir the soup occasionally, especially as it starts to thicken.
Taste the soup and add salt if needed. As a reference, we did not add extra salt to our chickpea soup.
Serve the chickpea soup with white rice or a nice piece of crusty bread for dipping.