Place the beans, carrots and potatoes in a saucepan or pot with lid or in a covered microwave-safe bowl. Add ½ cup water, and cook until vegetables are tender but not falling apart. Drain the vegetables before adding to the korma and reserve the cooking water.
Place the coconut milk and poppy seeds in a blender with ½ cup water and blend into a very smooth paste.
Heat oil in a large saucepan or pot over medium heat. Add the mustard seeds and when they pop, add one chopped onion and saute until it starts to turn translucent. Add ginger and garlic continue to saute another 30 seconds.
Add tomato puree with cayenne or red chilli powder, ground coriander, ground cumin, turmeric and garam masala, if using. Mix, cover, and let the tomatoes and onions cook over low heat about 10 minutes until they are darker. Stir occasionally to ensure nothing sticks to the pan.
Add the chopped bell peppers, green peas, and the cooked veggies. Add some water or vegetable stock from cooking the veggies to thin out the gravy to your liking.
Mix well and let the gravy come to a boil. Turn down the heat, cover, and let the vegetable korma cook another five minutes.
Stir in the blended coconut-poppy-seed paste and the garam masala, if using. Add salt to taste. Heat through but turn off the stove before the coconut milk comes to a boil.
In a small saucepan or skillet, prepare the tempering. Heat the remaining 1 teaspoon oil. Add cumin seeds and when they turn a couple of shades darker, add the curry leaves and stir-fry for a minute longer.
Turn off the heat and pour the tempering over the korma. Serve.