If time is of essence, I would suggest using seedless Tamarind since it makes this process much simpler. In a 2 litre/ 3L pressure cooker, add the deseeded tamarind (remove any fibres that you might find).
But if you don't find it or if that's what you have like me, this is how you would use it., remove as many seeds as possible and place it in the cooker. Add about 2 cups water
or enough to cover the tamarind.
Close the lid with weight. Cook on high for 4 whistles. "High" is when your flame covers the entire base of the cooker. If the flame comes up the sides, reduce it. If it does not cover the base, increase.
You will find in few minutes, the safety valve will stop jiggling and protrude
after which the whistles will follow soon after.
Once the whistles are done, switch off the flame and let the pressure settle.
Upon opening, give it a quick mash.
If you are using the seedless variety, just mash well and strain. If there are no fibres, you can just blend it either using an immersion blender or a blender. If it's too thick, add in little warm water. Otherwise just use a little less in your recipe. The kind of pulp will depend on the brand.
In the variety with seeds, don't use the blender. Take a strainer/colander with large holes, place it above a pan and mash/smoosh it using a spatula (silicone works best) to extract the concentrate. While using your hands would be much easier to squeeze the pulp out, it will unfortunately shorten the shelf life of your paste.
The tamarind paste will separate from the fibers and collect on the other side of the sieve and also in the bowl.
I have a plate with bigger holes than all my strainers, hence using that here.
A potato masher also works well to squeeze out all that delicious paste.
You can try adding a little water to the remaining solids and see if you can squeeze some more of the paste. Discard these fibres or use them to season your soups/rasam/sambar recipes.
Now your Tamarind paste is ready to be used.