Desalt the cod. Soak it in fresh, cold water, refrigerated, for 24 to 48 hours, changing the water at least five times. Drain well. Soak the chickpeas in a bowl with enough water to cover by 2 inches overnight or for 6 hours.
Place the cod in a medium saucepan, cover with 10 ¾ cups water and bring to a simmer over high heat. As soon as the water begins to simmer, remove it from the heat and remove the cod from the water (retaining the water). Allow the fish to cool, then shred it. Discard any bones. Set aside.
Make the stew. Heat the oil in a large, heavy soup pot or Dutch oven over medium heat and add the onions. Cook and stir until tender, about 5 minutes, and add the garlic and paprika. Cook and stir until fragrant, about 1 minute, and add the chickpeas and the water from the salt cod. Bring to a boil, add the saffron and bay leaf, reduce to medium heat, cover, and simmer for 1 hour. Add the salt, then cover and continue to simmer for another 30 minutes to an hour, until the chickpeas are tender. Add the potatoes and simmer for another 30 minutes, until the potatoes are tender and the broth fragrant. Stir in the spinach and pepper and remove from the heat. Let stand, covered, for 30 minutes to an hour while you make the salt cod balls.
Make the salt cod balls. Beat the eggs in a medium bowl and add the parsley, garlic, shredded salt cod, and breadcrumbs. Season to taste with the salt and pepper. Shape into 1 ½ -inch balls and set aside on a 10- by 13-inch parchment-lined baking sheet.
Taste the stew and adjust seasoning with a pinch of each of salt and pepper. Bring back to a simmer over low heat. Add the salt cod balls and poach gently for 5 minutes, or until cooked. Serve 360 ml. in a medium bowl.