Make the Spice Paste: In a spice mill or coffee grinder, grind the chana dal and raw rice to a fine powder.
Transfer to a small bowl and stir in the minced green chilies and 3 tbsp (45 ml) of water to form a paste.
Set aside.
Temper the Spices: Heat the ghee or sesame oil in a large, heavy-bottomed pan over medium heat.
Add the urad dal and fry for about 15 seconds until it begins to turn light brown.
Pop the Seeds: Add the black mustard seeds.
Once they begin to pop, immediately add the curry leaves and asafetida powder.
Cook the Paste: A few seconds later, pour in the dal-rice paste.
Cook, stirring, until the mixture dries out and becomes fragrant.
Sauté the Beans: Add the pre-steamed green beans, salt, and black pepper to the pan.
Sauté, tossing frequently, until the beans are heated through and coated in the spices.
Finish and Serve: Turn off the heat.
Stir in the grated coconut and your choice of fresh herbs.
Toss gently to combine and serve immediately.