In a 3 liter pressure cooker, take tur dal. Add turmeric powder.
Then, add 1.75 to 2 cups water and mix everything. If using a smaller size cooker, add less water.
Pressure cook on medium heat for 7 to 8 whistles or for 10 to 12 minutes till the dal is cooked very well and mushy. For a smaller cooker, less time will be required for cooking dal.
When pressure settles down naturally in the cooker, open the lid. Mash the cooked dal with a spoon. Keep aside.
Making Mamidikaya Pappu
Heat oil in a pan. Keep flame to low and add mustard seeds. Let them splutter.
Then, add fenugreek seeds and chopped green chili Instead of green chili, you can use 1 dried red chili (broken and seeds removed) or even can use both.
Fry till the fenugreek seeds change color. Keep heat to low or if the pan has become too hot, then you can switch off the heat. Then, add garlic cloves, crushed lightly or chopped.
Fry till the garlic turns light golden.
Then, add chopped onions and curry leaves.
Mix and begin to sauté onions on low to medium-low heat till they turn translucent.
When the onions become translucent, add chopped raw mango cubes and red chili powder. Mix well. For a spicier dal, you can add ½ teaspoon red chili powder.
Then, add water.
Cover the pan and cook the raw mango cubes till they soften. Do check in between.
Cook till the mango pieces soften. If you press the mango pieces, they should get mashed.
Now, add the cooked dal. Season with salt as per taste.
Mix very well. If the dal looks very thick, then you can add some water.
Cook on low heat for a few minutes or till the Mamidikaya Pappu comes to a boil.
Switch off the heat and add chopped coriander leaves. Mix again. Optionally, you can garnish with coriander leaves while serving.
Serve Mamidikaya Pappu with steamed rice.
Notes
You can also choose to cook the mango dal recipe in the Instant Pot or in a pan on the stove-top. If cooking on the stove-top soak the lentils for 30 minutes to 1 hour before cooking.
This recipe cannot be scaled due its complex flavors. If you do want to scale it then add the ingredients in approximation or by eyeballing them.