In a kadai (wok), heat 2 tablespoon oil. Add the tomato pieces to it. When the mixtures starts wilting add a lemon-sized ball of dry tamarind. Let the mixture cook uncovered till the tomatoes loose their shape and their juice evaporates.
In a separate pan, dry roast 1 teaspoon cumin seeds and fenugreek seeds.
In a blender grind the tomato mixture, cumin, fenugreek seeds, ginger, garlic, salt and red chillie powder. For a hot pickle add 3 tablespoon (45gm) of red chilie powder. For milder taste reduce the quantity as per taste.
In a frying pan heat 3/4 cup oil. Put 1 tsp mustard seeds, 1 teaspoon cumin, 1/2 teaspoon urd dal, 4 red chillies and curry leaves. When the mustard seeds splutter and the urd dal changes color, add the tomato mixture. Mix it well with the oil. Turn off the heat and keep refrigerated in an air-tight container for two weeks.
Make sure there is no water content in the pickle. Dry the pans and blender before using.