I would highly recommend sticking to the recipe the first time around to understand the concept, before making any changes until otherwise mentioned. Use only 2L Pressure cooker (should give a long whistle in around 2 minutes when 1/4 cup of water is heated on high flame). Start by adding the sesame oil to the pan. See Tip 1.
Followed by 1 cup water.
Add the Tamarind concentrate. See Tip 2 before adding.
followed by turmeric. Instead of 1/2 tsp you can just add 1/4 tsp as well. Add salt to taste. I added around 1 tsp of sea salt.
Close the lid and cook on high flame for around 4 minutes or 2 Whistles.
Don't let it cross the 5 minute mark. Simply switch off the flame in that case and check your pressure. The pressure might be leaking on the sides (time to change caskets in that case).
I think my first whistle came around 3:50 mark followed by the second one at 4:20. After 2 Whistles, switch off the flame and let the pressure settle down. You can also manually release pressure with the help of a spoon. Be careful to stay out of way from the releasing steam to avoid scalding your skin.
While that's cooking/settling, you can alternatively dry roast the spices. The powder can be your own recipe as well. This is the way my mother makes hence I follow the same spice powder esp given that the family prefers it.
When slightly brown, switch the flame
and grind it using a spice grinder/mixie to a fine powder.
P.S: I love to use my mortar and pestle for this for enhanced flavor/aroma. Also, for that arm workout when I am not in any time crunch. It does take time though I feel the results are worth the effort.
Now use the same skillet to Temper. Heat the pan and add the oil. Once hot, add the mustard seeds. When it stops popping, add the asafoetida and switch off the flame. Add the curry leaves.
Open the pressure cooker
and add the (1/4 cup) spice powder to it along with the tempering. You can also use some ghee for enhanced flavor. I usually add it to my steamed rice hence skip it here.
Give it a good mix until combined.
Close the lid back and let it sit for 10min. Don't have to heat it again.
You will find that it thickens on cooling.