Heat the oil in a large straight-sided skillet over medium heat. Add the mixture from the food processor with a pinch of salt and cook, stirring often, until the onions are light golden and tender, about 5-8 minutes. Stir in the garam masala, cumin and coriander and cook 30 seconds. Add the tomatoes (with their liquid), 2 cups of water, the chickpeas and a large pinch of salt. Bring to a simmer and cook 10 minutes, or until slightly thickened, stirring occasionally. Add the collard greens and cook 3-5 minutes, or until tender. Stir in the chopped cilantro. Taste and add additional salt as needed (sometimes I’ll also add a small pinch of sugar, especially if I use curry powder which can be more bitter than garam masala). Do Ahead: The stew can be made up to 2 hours ahead and left covered at room temperature. Reheat gently before serving. I think it’s best the day it’s made, but it also makes for a delicious lunch the following day.