Cut squash into inch square and 1/4 inch thick slices. Wash and in about a cup and a half of water, add tamarind paste and sliced squash.
Add turmeric, salt and cook on low heat till done.
Grind coconut, green chillies, 1/2 teaspoon mustard seeds and stir into cooked squash. Can wash out blender and add this water too.
Let mustard seeds splutter in oil, add fenugreek, red chilli, curry leaves and in a couple of minutes pour onto pachadi.
Variations: Instead of tamarind paste can use yogurt at the end. Can use cut okra or, okra and eggplant pieces, instead of squash.