Potato masala curry

This is yet another potato curry.This can be used as a main curry dish, Which can be used along with rice or chappathis.
U need

 potatoes                                             3  cut into small cubes
 onion( big)                                          2 cut into fine pieces - length wise
tomato                                                 2
ginger                                                  2 inch piece cut into small slender pieces
garlic  ( optional  )                                2 or 3
turmeric powder                                   1/4 spoon
pepper corn                                          10 - 15
red chilli powder                                   1/4 teaspoon
coriander powder                                  2 teaspoon
coconut                                                 1 cup (grated)
 Boil the potatoes with onion,ginger,garlic,turmeric,salt.Roast the coconut with pepper,coriander powder,chilli powder ,and grind it into a fine paste.Add the tomatoes to the poatoe mixture. Also add the ground paste.Cook it till becomes a homogeneous  mixture. Then do the tempering with  mustard seeds(1 teaspoon),red chillies(2 or 3),a few sprigs of curry leaves.  Your curry is ready.