1. Put the potatoes in a pot of salted water and bring to a boil. Reduce heat to keep at a simmer and cook until just tender–about 15 minutes. Drain them and let them steam dry for a bit.
2. While the potatoes are cooking, heat the oil in a large skillet over medium heat. Add the onion and garlic and cook for about 5 minutes, or until translucent. Add the cumin, cayenne pepper, curry powder, garam masala, ginger, and salt. Cook for 2 minutes more. Add the tomatoes, garbanzo beans, and potatoes.