1. If using dry chickpeas(1/3 cup), soak and cook them. Otherwise, 15oz canned chickpeas will do.
2. Put tamarind pulp(5 squareinches) in bowl with boiling water. Let sit for 15 minutes. Then, strain out and discard tamarind. We will use the water later.
3. Skin and dice optional potato(1). In nonstick pan, saute until cooked through. Set aside.
4. In separate pan, heat olive oil, saute onion(1) and green chili(1) for 10-15min. Then drain canned tomato(15 oz) and add it. Fry for a couple more minutes.
5. Add a bit of water to the Eastern chana masala mix(2 tbsp), then add it to the onion pan.
6. Combine the potato, tamarind water, jaggery(1 tbsp), and salt to taste. Serve hot.