In a large saucepan, combine mango, shallots, toor dal, chiles and turmeric with 4 cups of water. Bring to a boil. Reduce to a simmer and cook for 45 minutes - 1 hour, until dal is tender. Using an immersion blender, partially puree dal.
In a skillet, heat ghee. Add asoefetida. Once it stops spluttering, add mustard seed and cumin seed. Fry for 1 minute. Add garlic, red chiles and curry leaves until garlic is golden. Add to dal and simmer for 5 more minutes. Add more water, as needed, for desired consistency.