Wash carrots well in lot of water or under running water. Peel them and cut off both the ends.
Chop to ¼ inch pieces or grate them with a thick grater. Avoid using a thin grater as it makes the poriyal mushy.
Heat oil in a pan. Add mustard, urad dal, chana dal and red chili.
Saute until the dal turns golden. Then add green chili, ginger and curry leaves. Saute for a while until the curry leaves turn crisp.
Add hing, chopped carrots, turmeric and salt. Saute for 2 mins.
Cook covered for 2 to 3 mins on a low flame. This helps to release the moisture and cook the carrots. (If using grated carrots avoid covering the pan and just stir fry on a low to medium heat until tender.)
If the carrots are too dry and not tender, sprinkle little water. Cover and cook until soft and tender but not mushy. Taste test and add more salt if needed.
Add fresh grated coconut. If the heat from green chili is not sufficient you can also add little chilli powder or sambar powder at this stage.
Mix well and saute for a minute. Switch off and serve carrot poriyal with rice or roti as a side.