Take a frying pan and heat it on a low flame on your gas stove. When the pan is hot enough, add 1 cup of cumin seeds in it. Stir it continuously for a minute or so to dry roast the seeds on a medium to low flame.(Pro tip: Do not roast the cumin seeds fully. you will need to roast it more along with the coriander seeds that come next). Now, add ½ bowl of coriander seeds into the frying pan and stir them continuously.(Pro tip: Roast the two ingredients nicely now for about another minute or so until you smell the aroma of the roasted spices and notice fumes coming out). Check the spices closely for the color change. There must be a slight change in the color. Transfer the two spices to a bowl and put it aside.(Pro tip: The color of the coriander seeds will not change noticeably while the cumin seeds will become a bit darker in color, indicating they are roasted nicely). Now, in the hot pan add ¼ cup of black pepper, 6 pieces of dry red chilies of regular size, and 2 tsp of carom seeds.(Pro tip: Roast all these three spices together to optimize the flavor of the pani puri masala powder and not separately and at random). Stir the spices continuously until you notice the color of the carom seeds changed.(Pro tip: Adding carom seeds offers dual benefits. One, it enhances the flavor and taste of the pani puri masala powder, and two, the change in its color indicates that the other spices are roasted nicely and evenly). Also, when you notice the color of the dry red chilies turn a bit darker, transfer the roasted spices into the bowl containing the roasted cumin and coriander seeds you transferred before.
Now, add 1 cup of dry mint (pudina) leaves, ¼ cup of black salt, and ¼ cup of regular table salt.(Pro tip: It is important to keep the quantity of the two types of salts the same. So, you are free to change the amount of salt according to your preference). Stir them until the mint leaves become crispy. You may try crushing some to find whether it is roasted perfectly or not.(Pro tip: Do not skip roasting the salt well. This is important to ensure that it does not contain any moisture in it which may spoil the texture flavor, and taste of the masala powder). Now, put all the other ingredients that you set aside to cool back once again into the pan and give a final stir to mix them all.
When done, let the pan sit for some time so that all the spices cool off completely at room temperature.
When the spices are sufficiently cool, take a clean and dry grinder.
Transfer all the roasted spices into the grinder.
Now, add 1 tbsp of citric acid into the grinder.
Follow it with ½ cup of dry mango powder (amchur powder).
Grind the ingredients into a fine powder.
Check the texture and grind it further if it is not fine enough.
When you are satisfied, add 10 to 15 tablets of Hawaban Harde.(Pro tip: This is the magic ingredient of pani puri masala that most sellers use. You will get it easily in a grocery store). Grind it once again to blend everything nicely.
Check the taste of the powder and, if needed, add some more black salt to it. I did not find the taste to be proper so added some more black salt in it and mixed it nicely by running the grinder once again.
Finally, transfer the powder to a plate or a bowl, and your pani puri masala powder is ready to be used.