To make Alur dam for four to five people, take 500 g (1 lb) potatoes. Boil and peel them—in that order—and quarter them. Take 3-4 dry red chillies and 3-4 teaspoons of whole cumin seeds. Toast them in a dry frying pan over a medium flame until the chillies are dark brown. Remove and grind them as fine as you can in a pestle or on a grinding stone. (If, however, this seems too much trouble, take 3-4 teaspoons each of cumin and chilli powder and toast them together in a frying pan. The taste and flavour will be pretty good, though not as good as that of freshly ground spices.) Next, take 1½ teaspoons of tamarind extract and mix it smoothly in a bowl with 60 ml (2 fl oz) of hot water. Set aside. Heat 3 tablespoons of mustard oil in a karai and throw in 2-3 bay leaves, 1 teaspoon of panch phoron and a tiny pinch or ⅛ teaspoon of asafoetida crumbled between your fingers. As the panch phoron stops sputtering, put in the potatoes and sprinkle over them ¼ teaspoon of turmeric powder. Stir repeatedly until they turn golden brown and pour in 400 ml (13 fl oz) of water. Once it comes to the boil, reduce the heat to medium and simmer for four to five minutes. Then add salt to taste, 2 teaspoons of the roasted spices and the tamarind paste. Stir thoroughly for another three to four minutes and taste to find your balance of salt and sour. You can add more or less of the roasted powder depending on your tolerance for hot food. If the gravy becomes too thick, or too sour, more water can be added.