Heat the vegetable oil in a large skillet over medium heat. Stir in the onion, garlic, and cumin seeds. Cook and stir until the onion has turned golden brown; about 10 minutes.
Stir in the diced tomato, cayenne pepper, salt, turmeric, and coriander. Continue cooking 2 more minutes, then stir in the cauliflower, and reduce heat to medium-low. Cook until the cauliflower is tender, about 10 minutes, stirring occasionally. Add the kidney beans; cook and stir until heated through. Sprinkle with garam masala to serve.