Melt the coconut oil in a large, high-sided pan over medium heat. Add the onion and cook for 2 minutes, until just beginning to sweat. Add the jalapeño and garlic, and sauté for 1 minute, until just fragrant. Add the bell pepper and eggplant, and cook for 3 minutes, until the eggplant begins to soften.
Add the curry paste and brown sugar and stir to coat the vegetables, making sure there are no large clumps of curry paste. Pour in the coconut milk and stir to combine until the milk is stained from the curry paste. Stir the in diced tomatoes and chickpeas, and bring to a gentle simmer for 5 minutes.
Once the curry is simmering, add the spinach, half at a time, and stir until wilted. Remove the pan from the heat.
Garnish the curry with cilantro and serve over brown rice.