In a pressure cooker, cook the toor dal in about 2 cups of water until it is soft and mushy. Let it cool down and then drain the cooked dal water into a bowl and keep it aside.
In a pan, heat the oil and then add the mustard seeds, urad dal, asafetida, and the red chilies. Let it fry for a minute.
Now add the red pumpkin or any other vegetable of your choice, onions, tomato, curry leaves, and sauté for a couple of minutes. Then add the cooked dal water, jaggery, and salt. Cover the pan and let the vegetables cook.
Meanwhile, crush the garlic and pound the cumin and peppercorns in a mortar coarsely.
When the vegetables are cooked, add the tamarind pulp, Cooked dal, crushed garlic cloves, crushed cumin, and pepper, and also the cilantro leaves.
Cover the pan and let it cook for 10 more minutes.
Serve the Pondicherry sambhar hot with rice, ghee, and a vegetable on the side.