Wash and clean curry leaves in water until all dirt is completely removed. Keep curry leaves in a colander so that water drains out
Heat a flat skillet and dry roast coriander seeds mustard seeds, Red chillies, Fenugreek seeds, Cumin seeds and Fennel seeds in medium heat until the spices slightly turns its color and gets aromatic. Spread the roasted spices in a flat tray or a plate and let it cool down to room temperature.
Heat the same pan and dry roast till the curry leaves are well roasted. Make sure that neither spices nor curry leaves get burnt
Allow sufficient time for the spices and the curry leaves to come down to room temperature.
Add the roasted spices, curry leaves, turmeric powder and Asafoetida to the Mixer / Blender. Pulse to make a smooth mixture
Sambhar Masala can be used right away for making sambhar