Wash kantola, remove stem and cut into long pieces. Wash potatoes and cut into long finger chips like pieces, with the skin. Heat oil add asafoetida. After a minute add kantola slices and potato pieces. Mix turmeric powder and salt to taste. Cover and cook on medium heat. Stir often. When they are almost cooked, add remaining spices. Cook for five minutes more. Sprinkle coriander leaves.
Note: Kantola belongs to the family of karela. They are smaller and have fresh green color with soft poky skin.