Heat the coconut oil in a large skillet over medium heat. Add the onion and cook, stirring occasionally, for 8 minutes, or until softened. Add the cumin seeds, curry powder, garam masala, and salt and cook, stirring, for 1 minute, or until fragrant. Add the tomatoes, coconut milk, garlic, ginger, and chickpeas and stir to combine. Simmer, stirring occasionally, for 20 to 25 minutes, or until the curry has thickened. Stir in the water, adding more as needed to get it nice and saucy. Remove from the heat and add the lime juice and spinach, stirring until the spinach is wilted. Season to taste and garnish with cilantro. Serve with rice and/or naan.