Thaw frozen coconut or place dried coconut in a little warm water to plump up.
Cut squash in half, lengthwise. Then cut each half into half inch thick rounds, with large pieces cut into half again.
In a sauté pan, fit a steamer with water below, but just at a level that is below the steamer and not touching it. Place cut summer squash in the steamer basket. Cover and steam on medium heat for 10 minutes or until tender. When just cooked, immediately immerse the squash in a bowl of cold water to avoid overcooking.
In a blender, put in the roasted chana dal or almonds and grind until powder. Add in ½ teaspoon cumin seed and grind. Have about a 1 cup of water by the blender. Next, grind the coconut and green chili peppers, adding a little water to help the blades along. Next add in cilantro and slowly add just enough water, about ½-3/4 cup, to keep the blender blades moving to make a smooth paste. When you have a nice paste, add in yogurt. Blend well so that all of the paste is incorporated.
In the sauté pan, heat oil on a medium flame. When hot and shimmering, add in one black mustard seed. When the seed sizzles, add in ½ teaspoon black mustard seeds and asafetida. Keep a lid handy to cover the pan when the mustard seeds start to pop. When the mustard seeds are popping (few seconds), turn the heat to medium-low. Rub curry leaves between your fingers a little to release their natural oils and drop them and broken dried red chili pepper into the oil. Be careful, as moisture from curry leaves will cause the oil to spurt. Stir for few seconds until coated with oil.
Add steamed zucchini or yellow squash to the pan and coat with the oil and spices. Pour the coconut yogurt mixture from the blender into the pan. Add salt to taste. Put on medium heat and let the mixture boil once. Turn off the heat.
Serve majjige huli with hot rice. You can also chill it if you like, but traditionally at home, we would eat it after it was just prepared. If eating yogurt curry the next day, do not heat it.