Preheat the oven to 375° F. Prick the potatoes with a fork. Bake for 40 minutes, or until soft.
Cut the potatoes in half and scoop out the flesh. Heat the oil in a non-stick pan and fry the onion for a few minutes to soften. Stir in the ginger, cumin, coriander and turmeric.
Stir over a low heat for about 2 minutes, then add the potato flesh and garlic salt, to taste.
Cook the potato mixture for a further 2 minutes, stirring occasionally. Spoon the mixture back into the potato shells and top each with a spoonful of natural yogurt and a sprig or two of fresh coriander. Serve hot.Servings: 4