Pick, rinse and place dried chickpeas in a large bowl.
Pour 4 cups water over it and set aside for 8-12 hours. After the soaking time, you will see some white froth accumulated all over the chickpeas, discard it and rinse the chickpeas thoroughly under water multiple times. Drain the chickpeas in a large colander and set aside.
Place the steel insert inside your instant pot and switch it on. Press saute mode and once it displays hot add 1 tablespoon oil to it. Add 1 teaspoon cumin seeds, finely chopped onions, minced ginger and slit green chilies. Saute well in medium heat for 2 minutes. You can also add garlic and ginger minced.
Once done, add finely chopped tomatoes or tomato puree and mix well. Saute for a minute.
Add the chopped spinach and greens and mix well. You can also add just the spinach leaves.
Now add the spice powders namely 1 teaspoon garam masala powder, 1 tablespoon curry powder, 1/2 teaspoon red chili powder, 1/4 mango powder or amchur powder.
Mix and cook well for 3-4 minutes. Add 1/2 cup water to deglaze the pot and mix well. Now add the soaked and drained dry chickpeas. If you are using canned chickpeas or cooked chickpeas , drain it thoroughly and add.
Add 2 cups water. I have made this as a semi dry curry, you can add 3 cups water for a gravy curry. Also add salt to taste.
Close the instant pot, cancel saute and press pressure cooker mode. Set the timer to 30 minutes for dry chickpeas and 10 minutes for canned chickpeas. Let the instant pot pressure cook for the set time. Once done, let the pressure settle down naturally.
Open the instant pot and cook in saute mode for 3-4 minutes if you prefer a thick curry. At this stage you can add 1/4 cup thick coconut milk if you like a rich and creamy curry.
Add finely chopped cilantro leaves, lemon juice and mix well.
Serve Indian chana saag curry immediately. It is one of my favorite curries for weeknight dinner with basmati rice or brown rice.