Wash the chilies, remove the stem and roughly chop them.(use a mix of spicy and mildly spiced chilies)
Wash, peel and chop the ginger.
Heat oil in the pressure cooker, add cumin seeds and when they start crackling add asafoetida.
Now add the chopped chilies and ginger and saute for few seconds.
Add 1 cup water, close the cooker lid and cook on medium heat for 2 whistles.
Now let the mixture cool down and then grind the chilies ginger along with the water and make a fine puree.
If the puree is not smooth and fine then you can strain it using a sieve.
Add the pureed chilis in a pan and add 1/4 cup water in the mixie jar to remove the mixture left in the jar
Add 3/4 cup white vinegar in the pan and mix.
You can add 1 tsp MSG if you prefer.
Cook the sauce on medium heat till it start bubbling and thicken slightly.
Add 1 tsp cornflour in 3 tbsp water and mix well.
Add the slurry in the boiling sauce and keep stirring.
Addition of cornflour makes it smooth and thick and gives a nice texture to the sauce.(alternatively you can add a boiled mashed potato to thicken the sauce)
When the colour of the sauce change then do the plate test, take a tsp of sauce on the plate and check if it is thick enough or the pulp and water are separating
If liquid and pulp are separating then cook for few more minutes else it is done now.
let it cool down completely then store in a sterilized glass bottle and keep refrigerated.