Cook the potatoes in a large pan of boiling water for 20 minutes, or until soft. Drain, allow to cool and, peel off the skins. Cut the potatoes into large pieces.
Heat 1 teaspoon oil in a small frying pan (skillet) over medium heat, add half the aniseed and the rest of the spices and, stir-fry for about 30 seconds.
Transfer to a mortar and pound with a pestle or process in a spice grinder to a powder. Set aside.
Put the gram (chickpea) flour in a small bowl, pour in 250ml / 8fl oz (1 cup) water, and stir together until blended. Set aside.
Heat the remaining oil in a large frying pan over medium heat, add the mustard seeds and urad dal and, stir-fry for about 1 minute, or until they start to splutter. Add the remaining aniseed and stir-fry for a few seconds.
Add the chillies and onion and fry for about 2 minutes, or until the onion is translucent. Now add the potatoes and season with salt. Fry for about 1 minute.
Pour the flour paste into the curry and keep stirring until the sauce thickens considerably. Sprinkle over the ground spices, then pour over the ghee and add a few curry leaves. Mix well and cook for about 5 minutes, before removing from the heat.