Sabudana or Sago Upma

I recently rediscovered this dish, after a long long time. It's now a firm favourite, even being cooked at camp and experimenting on Aussies - they loved the crackly bits at the bottom where it gets stuck to the pan!!
Don't be afraid of the long list of ingredients, most of them are to be found in any Indian kitchen, or you can pop over to the Indian shop for them. Read the recipe before you start!

 1 cup sago (sabudhana)  Soak in 3 cups of water for 2-3 hours. The bowl should be large enough to accomodate the increase in size.
 2 medium potatoes
 Wash, peel, dice and boil in salted water for 10 minutes, till just done. Drain and keep dry.
 1/2 cup roasted peanuts
 Roughly crush, so that it is an irregular mixture. or try the Aussie version, 1/2  peanuts, and 1/2 macadamia nuts.
 1/4 cup canola oil, or olive oil.
 Heat oil in a pan, wok or kadai.
 1 teaspoon methi (fenugreek) seeds, 1 tsp cummin seeds, 1 teaspoon black mustard seeds
 Add to oil and allow to splutter
 2 chopped onions
 Add onions to pan and saute for 3 minutes, or till barely coloured.
 1" grated ginger
 Add ginger and fry till the raw smell vanishes.
 A sprig of about 10 -12 curry leaves
 Add curry leaves and stir.
 1 teaspoon turmeric powder  Add to pan and stir.
3 green chillies chopped (optional)
 Add to pan and stir.
   Drain the sago gently and add to the pan. Stir firmly but gently, moving the sago from the edges and bottom, and not letting it stick.
   When all the sago is well mixed into the spices, turn the heat down and put the lid on briefly, for a minute or two.
   Add the potatoes and mix them through the sago. Mix the sago well. If the mix looks a bit dry, wet you hands and flick water into the pan.
   Add the crushed peanuts and mix them through. Put the lid on, and allow to cook for a minute or two. By now the sago should be turning transparent.
 1 cup chopped green coriander
 Add the coriander and mix through the sago.
 1 or 2 limes or lemons
 Squeeze the juice over the mixture, and mix well.
 1 teaspoon salt
 Add salt and mix well.
   Put the lid on and let it steam quietly for 2-3 minutes. Turn off the heat. Mix thoroughly, scraping up the slightly crispy bits, and serve immediately.

Serve with additional chopped coriander and wedges of lime for people to squeeze over the upma.