Soak split peeled moong beans at least 1 hour. Drain.
Add ghee to heavy bottomed saucepan and turn on medium heat.
Add garlic and allow to lightly brown.
Add cumin, garam masala and cinnamon stick and fry 30 seconds more.
Add fresh grated ginger, sugar and cayenne.
When the mix begins to caramelize and turn a reddish brown color, add the moong beans and stir-fry one minute.
Add the water, turmeric and optional tamarind.
Bring to a boil and reduce heat to a simmer.
Cook 2 hours.
Notes
* This dish can be made in a slow-cooker relatively effortlessly. Set it on high. Add the water, moong beans and turmeric. Stir-fry the rest of the spices and add to the slow-cooker. Cook until soft.