Cut potatoes into cubes and break cauliflower into small florets.
Heat vegetable oil in a skillet, crackle cumin seeds, and sauté chopped onion with ginger paste until soft.
Add potato cubes, cauliflower florets, green peas, turmeric powder, red chili powder, and salt.
Cover skillet tightly and cook on low heat for 15 minutes, stirring occasionally until vegetables are tender.
Serve warm with rotis.