In a wok or large skillet, heat the oil over medium-high heat. Add the onion and cook until the edges are browned, about 4 minutes. Stir in the tomatoes, coriander, cumin, garam masala and turmeric. Lower the heat to medium and cook for 3 minutes more.
Stir in the chickpeas, add the salt and cook until heated through, about 5 minutes. Add the spinach and cook about 5 minutes more.