Add instant oats, roasted gram dal, rice flour, curd, cumin seeds, green chilli, spinach, coriander leaves, ginger, salt, and water to a blender. Grind everything together into a smooth batter.
Add more water if required and adjust the consistency. The batter should be slightly thicker than dosa batter.
Add chopped onion, corn, fresh peas, and carrots to the batter. There is no need to cook the vegetables separately, as they will cook while preparing the paniyaram. You can also add any vegetables of your choice.
Heat ghee in a small pan. Add mustard seeds, urad dal, and chana dal. Once they splutter and turn golden, add this tempering to the batter and mix well.
Heat a paniyaram pan and grease the cavities with ghee. Pour the batter into each cavity.
Cover and cook on a low flame until the paniyarams turn golden and are cooked well.
Flip and cook the other side until done.
Serve warm as a healthy breakfast or snack for babies and toddlers.