In a large kettle, heat water or oil over moderate heat, add onions and cumin seeds, then cook 5 -- seven moment, until onions are browned around the edges. Add the garlic and ginger, cook 1 to 2 minutes longer. Add the garam masala, turmeric, garam masala, cayenne and cook for 1 -- two minutes, or until aromatic and sweet. Add tomatoes and cook 4 minutes, until they breakdown a little. Add tomato paste, chickpeas and coconut milk, then stir to blend and bring to a gentle simmer, stirring periodically. Adjust seasonings to taste.