Roast the rava in a tbsp of ghee till it turns golden.
Add 1 cup of milk. Mix well and let it boil till the rava is cooked well and becomes soft.
Mix the cocoa powder well in 1/4th cup of milk and add it to the cooked rava. Add the rest of the milk, sugar and vanilla essence and mix well. Let it cook on a medium flame for few mins till it becomes thick.
Heat the remaining ghee in a pan. Add the chopped walnuts and sauté till it turns golden.
Garnish the payasam with walnuts and choco chips and serve it warm.