Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   1      pound         potatoes
   2                    green chiles -- finely chopped
   1      pieces        ginger -- (1" long), scraped,
                        -- finely chopped
   2      medium        onions -- finely chopped
   2                    tomatoes -- finely
                        -- chopped,(opt)
                        salt -- to taste
     1/2  teaspoon      ground turmeric
   1      cup           water
     1/2  cup           green peas -- boiled, (opt)
   1      small   bunc  coriander -- finely chopped
                        ***For Tempering***
   1      tablespoon    oil
   1      teaspoon      brown mustard seeds
   1      teaspoon      cumin seeds
   1      teaspoon      black gram dal
   1      teaspoon      Bengal gram dal
   1                    red chile pepper -- halved
     1/2  teaspoon      asafetida powder
                        a few curry leaves

Preparation:

Pick over and wash the dals. Boil the potatoes in their jackets until cooked. Peel, mash and set aside. TEMPERING: Heat 1 tablespoon oil in a heavy saucepan. Add the mustard seeds, cumin seeds, black gram dal, Bengal gram dal, halved red chile, asafetida powder, and a few curry leaves. When the mustard seeds splutter, add the finely chopped green chiles, ginger, onion and tomatoes (if used). Sauté for 2-3 minutes. Add the salt to taste, ground turmeric, and 1 cup water. Cover the pan with a lid. Simmer for about 5 minutes, until the onions are well cooked. Add the mashed potatoes and boiled peas (if used). Cook for another 2 minutes, until thoroughly blended. Garnish with finely chopped coriander leaves. Serve hot with Masala Dosai or puris.