Heat oil in a deep skillet or pan. Add cumin seeds and mustard seeds, and let them splutter. Add green chili and onion, and sauté until the onion is soft.

Add the chopped tomato and cook until it softens.

Add green peas and sweet corn. Then add salt, oats, and all the spices. Mix well.

Reduce the heat to low. Add water as needed and pour in the tomato sauce. Mix everything together.

Cook, stirring, until the mixture thickens. Add lemon juice, mix well, and serve hot.