Wash and pat dry the beans.
String them and cut them into 1 cm pieces. Set it aside till needed.
Chop the carrots into 1 cm cubes and set it aside.
Into a frying pan, on medium heat, add the oil and mustard seeds
Once the mustard seeds crackle, add the urad dal, channa dal and red chillies.
When the dal turns golden, add the curry leaves followed by the chopped beans and carrot ( optional, see notes below)
Stir fry for a minute, add the salt and turmeric powder.
Mix well add 2-3 tablespoon of water and cover and cook for 4-5 minutes.
Open the lid carefully after 5 minutes, add the coconut and stirfry for another minute.
Remove from heat and serve warm.