Black chickpea stew

Name: Black chickpea stew
Ingredients: 1 cup black chickpeas, known as kala chana; 1 cup onions, finely chopped; 1 tablespoon garlic, minced; 1 tablespoon ginger, minced; 1 cup tomatoes, chopped; a small handful of coriander leaves, chopped; 2 tablespoons oil; Dry Spices:; 2 teaspoons Coriander powder; 1 teaspoon cumin powder; 1/2 teaspoon turmeric; 1/2 teaspoon dry mango powder, called amchur; 1/2 teaspoon garam masala; 1/2 teaspoon cayenne pepper powder, optional; 1 bay leaf; salt to taste