Make the Rice Salad:
Mix together the cooked rice and the vegetables.
Put the coconut milk, rice wine vinegar, sambar powder, pepper and salt in a blender and blend about 30 seconds.
Pour this over the rice and vegetables. Add the mint or basil. Mix gently with a fork taking care not to smash the grains of rice.
Make the Potato Sabzi:
In a cast-iron skillet, heat the oil.
Add the cumin seeds and when they sputter, add the asafetida and udad dal.
When the dal turns lightly golden, add the green chilies and ginger
Stir quickly, then add the onions.
Cook until softened, about 3-4 minutes.
Add the potatoes and stir to coat with the spices.
Cook over medium heat, stirring occasionally, for another 3-5 minutes.