Place grated coconut, cumin seeds, garlic cloves, and green chillies in a blender. Add a little amount of water, and grind them to a very smooth paste. Set aside.
Meanwhile, place diced mangoes, ground turmeric, salt, and curry leaves in a deep bottomed pan. Add water just enough to cover the mangoes. Cook over a medium- high heat.
When half done, add the coconut paste. Stir well, and cook again until the mangoes are well done. Check the seasoning, and add more salt if needed. Set aside.
Now place another pan over medium heat. Add oil and mustard seeds. Allow to splutter. Throw in dried red chilli, and curry leaves. Fry for a while. Turn off the heat, and add the tempered spices to the mango curry. Mix well, and serve.