Soak the red cowpeas in water for about half an hour if possible, as this will improve the health benefits and make the cowpeas more soft.
Remove the water used to soak the cowpeas and transfer the red cowpeas to the pressure cooker.
Add 3 cups of water to the pressure cooker, mix everything well.
Close the lid of the pressure cooker and cook in medium to high heat for about 12 minutes or until 3 whistles have come. (Make sure you are correctly following all the guidelines while using the pressure cooker including the use of safety valve, as these guidelines are important for the purpose of safety while using pressure cooker).
After 12 minutes or 3 whistles, the red cowpeas should be cooked, you can switch of the stove and wait for the pressure cooker to cool off.
Once the pressure cooker is cooled enough, open the lid and see if the peas is cooked completely. If there is excess water remaining, you can drain the water off or save the water as it makes a healthy broth for soups and stews.
Add the finely grated coconut, garlic powder and remaining spices to the cooked cowpeas (vanpayar) in the pressure cooker and mix well and cook for another 2 minutes so everything gets well cooked and mixed. This method works well for me as the coconut I buy here is very finely grated.
Instead of adding the grated coconut and spices directly, you can coarsely grind the grated coconut and spices (turmeric powder, red chili powder, garlic and cumin seeds powder) in a food processor and add this mixture to the cooked cowpeas (vanpayar) and make the thoran. The South Indian Kerala style vanpayar thoran or red cowpeas with coconut is ready to serve with rice or rice soup you wish. For best results, serve the cooked dish hot or warm with rice!