Finely chop the onion, tomatoes, and green chilies.
In a large pan or skillet, heat oil over medium heat. Add cumin seeds and mustard seeds. Once they splutter, add chopped onions and green chilies. Sauté until the onions turn golden brown.
Add ginger-garlic paste to the sautéed onions. Cook for an additional 1-2 minutes.
Add chopped tomatoes, turmeric powder, coriander powder, red chili powder, and salt. Cook until the tomatoes are soft and the oil begins to separate.
Add the frozen peas to the pan. Mix well with the spice mixture. Cover the pan and let the peas cook on low to medium heat for about 8-10 minutes, or until they are tender.
Sprinkle garam masala over the peas and mix well. Cook for an additional 2-3 minutes.
Serve hot with cooked rice or your favorite flatbreads.
