For the masala sauce: Blend the ginger, garlic, green chiles, and lemon juice to a paste in a food processor. Add a splash of water to loosen and bind the mixture. Stir in the cilantro and blend again until the cilantro is well combined, but retains its texture. Add the coriander, cumin, carom, coconut, salt, sugar, and roasted peanuts, and stir well until combined.
For the curried vegetables:
On a sheet pan lined with paper towels, place the aubergine pieces. Sprinkle salt over the aubergine, and place paper towels on top. Place a heavy skillet over the aubergine to press out the excess moisture. Set the pan aside for 30 minutes. Quickly rinse the aubergine of the salt, and pat dry.
Heat the oil in a nonstick pan over a medium heat, and add the asafoetida, and fry for 20 seconds, or until fragrant. Add the mustard seeds, and fry for 30 seconds, or until they start to pop. Be careful of the popping seeds and splatters of oil. Add the potatoes, aubergines, sweet potato, and parsnip pieces, and fry for 3 to 4 minutes, stirring regularly, or until the vegetables are golden brown.
Stir in the masala sauce, add the water, and bring to a boil, then cover the pan with a lid, reduce the heat and simmer for 20 to 25 minutes, shaking the pan occasionally. Once the vegetables are just tender, add the tuvar beans, cover with a lid and cook for a further 2 to 3 minutes, or until warmed through.
To serve the dish: Divide the Gujarati Undhiyo among 6 serving plates and sprinkle over the fresh chopped cilantro, and freshly grated coconut, to garnish.
*Can be found at specialty Asian or Indian markets. The potato takes the longest time to cook and the sweet potato the least, so make sure you cut the sweet potato up into the biggest pieces or it will over-cook and break down in the pan. Also, be sure to taste the masala before adding it to the pan and over-season a little. The vegetables will absorb some of the salt and if you don't add enough salt, the dish will seem a little bland.