About 4 large potatoes or 24 small (not baby) potatoes. If you use large potatoes, chop them into ¼-inch cubes. If you are using small potatoes, halve or quarter them.
6 tbsp poppy seeds, covered with ½ cup of water and soaked for about an hour. Blitz this mixture in a blender to get a smooth paste.
2 green chillies, slit down the middle
1 tbsp coconut or mustard oil
Salt to taste
2 tsp panch phoron (I usually mix 1 tsp each of cumin, mustard, fenugreek, fennel and kalonji seeds and store the remainder in an airtight bottle. Since these are whole spices, they won't spoil easily, unlike powdered ones. Panch phoron is great in dals too.)
Heat the oil in a wok or kadhai.
Add the panch phoron and, when the seeds sputter, add the green chillies. Stir-fry for about 30 seconds.
Add the potatoes and stir-fry them for about two minutes.
Now add the poppy-seed paste, salt to taste, and about ½ cup water. Mix everything together well and when the mixture starts to simmer, place a tight-fitting lid on the wok, turn the heat down to medium-low, and let the mixture cook until the potatoes are tender. Stir occasionally. If the water has evaporated before the potatoes are cooked, add a few teaspoons more at a time so the potatoes and poppy don't burn.
Once the potatoes are cooked, turn off the heat. Garnish with coriander, if you like, and serve hot.
Recipe by Holy Cow! at http://holycowvegan.net/2012/08/aloo-posto-with-new-potatoes-from-my.html