Take a frying pan and heat it on a low flame on your gas stove. When it is hot, add a cup of split chickpeas (chana dal) to the pan.
Follow it with a cup of black gram split (mash dal).
Now, add 1 cup of split pigeon peas (toor dal) to the frying pan.
Stir all the lentils in the frying pan continuously to dry roast them for about 5 minutes.
Remove the pan from the gas stove when you notice the color of the lentils has changed, indicating they are roasted nicely and there is no moisture in them. Transfer them to a plate and keep them aside to cool.
Now, add 1 cup of coriander seeds in the same pan.
Stir them continuously for about a minute until they are roasted nicely and you notice a slight change in their color.(Pro tip: Remove the pan and transfer the roasted coriander seeds immediately to the plate to prevent them from being over-roasted). Now, put ½ cup of fenugreek seeds and ½ cup of cumin seeds into the pan.
Roast them nicely by stirring them continuously for about a minute or two and you notice their color change to a slight golden brown. Keep them aside.
Now, put 1 cup of fresh curry leaves into the pan.
Stir them continuously for about a minute so that they lose their moisture and do not get burnt but become crisp.
Now, put 12 to 15 pieces of dry red chilies into the pan. Stir them and roast them nicely until they emit their natural aroma.
Now, take a clean and dry grinder.
When the roasted spices and lentils are cool enough, transfer them all and the red chilies to the grinder.(Pro tip: If your grinder is small, you can grind the ingredients in small batches. However, make sure you add the subsequent ingredients in appropriate portions as well). Add ¼ cup of garlic without their skin to the grinder.
Follow it with 1 tbsp of regular table salt.
Grind the ingredients to a fine powder.
Take a clean and dry bowl.
Transfer the powder from the grinder to the bowl and your sambar masala powder is ready to be used.