Place the poppy seeds in a nonstick skillet over medium-high (not smoking) heat. Gentle stir and cook seeds for one or two minutes so that they are toasted but not burned.
Grind the roasted poppy seeds along with the green chillies and a few tablespoons of water to a very fine paste. Set aside.
Heat half of the oil in a pan for 2 minutes till very hot. Shallow fry the cubed potatoes in batches on medium heat till they are lightly browned. If needed, sprikle one or two drops of water to keep the potatoes from sticking. Drain on a paper towel and keep aside.
Now, heat the remaining oil in the same pan. Add the whole dry red chillies and turmeric powder. Fry briefly. To this, add the poppy seed paste and fry again on medium / low heat for 5 minutes till the oil has left the sides of the pan.
Add now the fried potato cubes and mix well. Add water and salt. Stir, cover and keep on low heat for 15 minutes till the potatoes are soft.