Steps
1. Heat oil in a pan over medium heat. Add mustard seeds and cumin seeds; let them splutter.
2. Add sliced onions and sauté until golden brown.
3. Add chopped tomatoes and cook until they soften and oil begins to separate.
4. Add turmeric, red chili powder, garam masala, and salt. Mix well.
5. Cook the mixture on low heat for 5-7 minutes, stirring occasionally.
6. Garnish with chopped coriander leaves before serving.
7. Serve hot with steamed rice or Indian flatbread.