Heat a large pan on medium high heat and add oil.
Fry the mustard seeds and cumin until fragrant, about 2 minutes.
Add the onions and ginger and sauté until tender and translucent (about 4 minutes)
To the onion mixture, add tomatoes, veggie stock, and spices.
Bring to a simmer and using a potato masher, smash the tomatoes to a paste.
Add the chickpeas, cover, and simmer on medium heat for 15 minutes.
Garnish with cilantro and serve with rice or naan.
Spice level is always a personal preference. Feel free to add less, more, or omit the chili powder all together.