Combine toor dal with water and turmeric either in a stovetop pressure cooker or in an Instant Pot. Cook till the lentils are very soft and mushy. About 3 whistles in a traditional pressure cooker and 8 minutes in Instant Pot.
In a medium size saucepan on medium heat, add oil. Once the oil is hot enough, add the fenugreek, mustard & cumin seeds. Once the seeds start to splutter, lower the heat and add the dry red chilies. As they turn bright red, stir in the curry leaves and asafetida.
Next add the mango pieces; cover and cook for 10~15 minutes or until they turn tender.
Add salt and cooked dal and simmer for 4~5 minutes. Add more water if the mixture looks too thick. Stir in jaggery, if using, in the end. Mix well and serve.
If your mango is not sour enough, then feel free to add some tamarind paste.
Use dried red lentils or masoor dal instead of toor dal. Cook red lentils for 6 minutes on High Pressure in Instant Pot and for 2 whistles in traditional pressure cooker.
Frozen sliced raw mango is a great substitute when fresh mangoes are not available. Use about 1 cup of mango slices in the recipe.
I prefer cooking dal and mango separately because the sourness in mango prevents the lentils from becoming soft.
If you prefer to make this a one pot dish - then cook toor dal until soft. Then add the mango pieces and cook for 1 more whistle or 2 minutes on High pressure in an Instant pot. Add tadka separately.
Add 2~3 crushed garlic cloves instead of asafetida for a different flavor.
Add ½~1 teaspoon red chili powder to add spiciness to mango pappu.
Leftover mamidikaya pappu can be stored for up to 3 days in an airtight container in the fridge.
Mango dal can also be frozen for up to 2 months.
You can also add 3~4 cups of chopped spinach to make spinach mango pappu.