Heat a large stockpot over medium heat and add oil. Add onion, ginger, and garlic. Cook, stirring frequently until onions are soft and translucent, about 10 minutes. Add cumin and stir for 30 seconds. Add chickpeas, lemon, tomatoes, and cinnamon; cook until tomatoes soften slightly, about 3 minutes.
Season chicken with 1 1/2 teaspoons salt and 1/2 teaspoon pepper; add to pot. Add 1 1/2 cups water, nestling chicken into liquid. Bring to a boil. Reduce to a gentle simmer and cook, partially covered, until chicken is cooked through, about 40 minutes. Remove chicken.
Continue cooking over high heat to reduce slightly if necessary, crushing some chickpeas to thicken. Stir in cilantro. Taste and adjust for seasoning. Spoon chickpeas and liquid into serving bowls, top with chicken. Sprinkle with cilantro and serve with lemon.