In a large pot, combine 2 1/2 cups of vegetable broth, 2 cans of drained and rinsed chickpeas, 1 can of fire-roasted tomatoes, 6 potatoes, 1 cup of diced onion, 1 tablespoon of unsalted butter, 2 teaspoons of crushed ginger, 2 teaspoons of salt, 1 teaspoon of ground cumin, 1 teaspoon of ground coriander, and 1/2 teaspoon of cayenne pepper.
Stir the ingredients to mix them well.
Nestle the potatoes into the liquid.
Set the pot uncovered over medium heat.
Simmer vigorously for about 35 minutes or until the potatoes are tender.
Serve the curry in bowls with Indian naan bread or over rice.