Peel arbi and wash thoroughly. Now chop arbi in 1/4 inch round and thick pieces.
Wash tomatoes and cut in big pieces. Remove stalk of green chilies and wash thoroughly. Peel ginger, wash and dice in big pieces. Now grind these all ingredients to make a fine paste.
Preheat ghee in a pan. When ghee is sufficiently hot add arbi pieces into it and fry on medium flame until they turn slightly brown in color. Once fried, take them out in a plate. Likewise fry all arbi pieces. Now add lotus seeds in ghee and fry until they slightly brown in color. Take them out in a separate bowl. Reduce the flame and add carom seeds in leftover ghee. After sauteing carom seeds add asafoetida, turmeric powder, coriander powder, dry fenugreek leaves and saute for few more minutes.
After this add tomato-green chilly-ginger paste in the wok. Also add red chilly powder, stir constantly and roast the masala until oil starts separating from it.
After sauteing the masala nicely add 2 cup (500-600 ml) water into it. Now add salt, garam masala and fried arbi pieces. Cook the jhol until it simmers once. Now reduce the flame and cook for 3-4 minutes.
Add lotus seeds and green coriander into it. Mix well. Arbi jhol sabzi is ready, take it out in a bowl. Pour some ghee over the curry, this enhances the flavor. Garnish with green coriander leaves. Serve steaming hot arbi jhol with poori and parantha and relish eating.