Heat the oil in a large pan Add red chilies, chana dal, urad dal, cumin seeds. Stir and once they turn golden color add mustard seeds. After the mustard seeds are done popping, add curry leaves and turmeric powder. Add chopped onions and green chilies and saute for a min. Add 1 tsp salt. Seed out the papaya and cut into small bite-sized pieces add the chopped papaya to the pan and fry for 3 min. add 1 tsp salt. Close the lid then simmer on low or medium heat for 10 minutes. Now you will see the curry becomes like gravy, then add milk to the pan. and cook on low for 5 minutes. Taste and adjust the spices and turn off the heat. Close the lid and let flavors sink into curry.