Heat oil in a pan over medium heat and add cumin seeds. Let them sizzle.
Add chopped onions and sauté until golden brown.
Stir in minced garlic, ginger, and green chili. Cook for a minute until fragrant.
Pour in the tomato puree and cook until the oil separates.
Add turmeric, coriander powder, red chili powder, and salt. Mix well.
Toss in the diced potatoes and cauliflower florets, stirring to coat with spices.
Cover and cook on low heat for about 20 minutes, stirring occasionally, until vegetables are tender.
Sprinkle garam masala and mix well.
Garnish with fresh cilantro and serve hot with naan or rice.