Boil 5 cups of water with tea bags; after tea comes to boil turn down the heat to medium low. Let it boil for another 2 to 3 minutes. Take out the tea bags and keep aside.
Wash chickpeas well and soak in tea water for about 8 hours. Chickpeas after soaking will become about 2 1/2 times the volume of the original.
In pressure cooker add chickpeas with the water they were soaked in, plus 2 more cups of water. Close the cooker and put the pressure on. Cook on medium high heat.
As pressure cooker starts steaming turn the heat down to medium and cook for about 15 minutes.
Close the heat and wait until steam has stopped before opening the pressure cooker. Chickpeas should be soft and tender.
Blend the tomatoes, ginger and green chili to make paste.
Heat the oil in a saucepan. Test the heat by adding one cumin seed to the oil; if it cracks right away oil is ready. Add cumin seeds, and as the cumin seeds crack add basen stir-fry until basen is light gold brown.
Next add tomato paste, coriander powder, and black pepper. Stir-fry for 2 to 3 minutes until the oil is separating from the mixture and tomato mixture should be about half in volume.
Add spice mix, salt, garam masala, and mango powder to chickpeas. While mixing, lightly mash the chickpeas. Adjust salt, pepper, and sourness to your taste.
Cook on medium high heat. After choles come to boil lower the heat to medium low and put the lid on.
Choles are ready to eat in as little as ten minutes, but for best taste let simmer for 30 minutes, stirring every 5 or 6 minutes.
Garnish choles with shredded ginger and sliced green chili.