Heat the oil in a saucepan and add the whole spices -- the bay leaf, cardamom, cinnamon and cloves. Finally add the cumin and stir to mix. When the cumin sizzles, add the onions with some salt and cook until the onions turn golden-brown.
Add the ginger-garlic paste and saute for a minute.
Add the cayenne and turmeric, saute for another minute, then add the diced tomatoes. Mix well and let the tomatoes cook, stirring them frequently, until they are completely broken down and very pulpy.
Add the chickpeas along with 2 cups of water and stir well. Add the chana masala spice mix. and stir it in.
Bring to a boil, turn heat to low, cover and simmer about 15-20 minutes so all the flavors merge. You can use a potato masher to mash some of the chickpeas and thicken the sauce. If the chana masala looks too dry, add more water.
Squeeze in the lemon juice and garnish with coriander leaves, if using.