This variation on the Indian classic is cooked long and slow for maximum flavor development. Adapted from a recipe by Shiv at Pithy and Cleaver. http://bit.ly/2kb6og (My slow cooker variation will take about 9 hours total.)
In a large, heavy Dutch oven, heat oil over medium heat until shimmering. Reduce heat to low and add star anise, cinnamon, cloves, mustard seed, peppercorns and cardamom pods. Cook slowly, stirring occasionally, 30-45 minutes, until the mustard seeds are nearly burnt. Using a slotted spoon, scoop out and discard the spices, leaving the oil in the pan.
Add onion to oil and continue to cook very slowly, stirring occasionally, 2-3 hours, or until onions are completely limp and dark mahogany brown. (Slow cooker variation: strain the oil from step 1 into a slow cooker. Add the onions and cook on low 6-8 hours, stirring every 2 hours. Leave the lid ajar to allow steam to escape or your onions will stew instead of browning.).
Add tomato paste and water (or stock) and simmer 10 minutes. Add chickpeas and simmer 20 minutes more. (Slow cooker variation: add tomato paste, water and chickpeas to onions and cook 1 hour on high.).
Add yogurt and garam masala; simmer a final 10 minutes, then serve with steamed basmati or jasmine rice.