In a medium pot over medium-high heat, heat the olive oil; add the onion. Stir frequently until the onion is soft, about 3 minutes. Add the garlic and ginger. Cook, stirring, until it's very fragrant, about 1 minute. Add the cumin, coriander, turmeric, and red pepper (if using). Cook, stirring, 30 seconds. Add the broth, increase heat to high, and bring the mixture to a boil. Stir in the chickpeas, cover, and cook until the flavors blend and the chickpeas are heated through. Uncover for about 2 minutes until most of the liquid is absorbed. Add salt and lemon juice to taste. Serve hot, topped with parsley.