Put the rice in a medium saucepan. Cook according to package directions. Lower the heat so it bubbles gently but steadily; cover and cook, undisturbed, until the rice is tender and the water is absorbed, 25 to 30 minutes (check only toward the end of cooking time). The rice should be studded with craters, or steam holes when it is ready. Remove the pan from the heat and keep it covered.
Meanwhile, heat a large cast iron or metal skillet with a high rim over medium heat. Once hot, add vegetable oil and sauté onions, garlic, and ginger. Add a pinch of sea salt and continue for about 10 minutes, stirring frequently until softened.
Add the curry powder and turmeric fry for a minute to release aromatics.
Add the coconut milk, cilantro, lime juice, vegetable broth, chickpeas, carrot, mango, cashew nuts, and the remaining salt, with enough water to roughly cover. Bring to the boil and simmer on low heat for 10-12 minutes or until carrot is cooked through.
Stir in spinach. Bring to boil then simmer on low heat for 2 minutes or until wilted.
Serve the curry atop the rice. Sprinkle with additional cilantro and lime as desired.