Remove the skin of the bottle gourd and chop it. Heat oil in a pan. Add cumin seeds and fenugreek seeds to crackle. Soak chana dal for 4 - 5 hours. Strain it and add in the pan. Add red chilly powder,turmeric powder and mix well. Add one cup of water and cover the pan ,cook in a slow flame for 10 mins. Add finely chopped tomato and bottle gourd and mix well. Add half cup of water and cook in a slow flame. When water absorb it add salt and mix well. Garnish with coriander leaves and serve.