Place a small frypan on medium heat and add the cumin seeds. Toast them until they darken and become aromatic, then remove them from the heat. When cool enough to handle, grind to a fine powder. Set aside.
Remove the stalk from the green chilli and slice lengthways into halves. Carefully scrape out the seeds and white pith, and discard. Finely slice the green chilli.
Place the yoghurt in a small bowl and whisk until smooth.
Add the carrots, reserving some for garnishing, and the chopped green chilli. Mix well.
Add the ground cumin seeds, garam masala and black salt. Mix well.
Cover, and refrigerate until ready to serve.
to serve
Heat the ghee in a small pan. Tilt the pan to keep the ghee contained in a small puddle, then add the asafoetida. Heat for just a few seconds, then pour over the raita.
Garnish with the reserved carrot and serve.
notes
Removing the seeds and pith from the green chilli will remove most of its heat.
Black salt is available from Indian grocers. If unobtainable use regular table salt.