How to Make It
In a large saucepan, combine the cucumber, potato, carrot, beans, tomato, the halved chiles and 2 tablespoons of the vegetable oil. Add the water and turmeric and bring to a simmer over high heat. Reduce the heat to moderate, cover and cook, stirring occasionally, until the vegetables are tender, about 10 minutes.
In a food processor, combine the sliced chiles, coconut, shallots, garlic and cumin seeds and process to a paste. Stir the paste into the vegetables and simmer for 4 minutes.
In a small skillet, heat the remaining 3 tablespoons of oil until shimmering. Add the curry leaves and fry over high heat until sizzling, about 10 seconds. Add the oil and fried curry leaves to the stew, along with the banana and simmer for 1 minute. Stir in the yogurt. Season with salt and serve.
Steamed white rice.