In a large saucepan, heat the oil over medium-high heat. Add the mustard seeds, cumin seeds, and curry leaves. Let sizzle for 1 minute. Add the onion and the jalapeño chili and sauté for 2 minutes. Add the turmeric and cook, stirring often, until the onion is translucent, about 4-5 minutes. Add the chana dal and 1 1/2 cup of water. Cover and cook until the chana dal is halfway cooked, about 5-10 minutes. Drain tamarind reserving water. Using your fingers, remove the flesh from the pods and add to dal, along with soaking water. Add gongura, salt and chili powder, and more water, as needed. Cover and cook 5-10 minutes more, until fully cooked. Bon appétit!