In a mixer jar, add 1 cup besan, 1 cup curd, and 1 cup water. Also, add salt to taste, ½ tsp turmeric powder, 1 tsp red chili powder, 1 tsp coriander powder, 1 tsp cumin powder, and 1 tsp sugar. Grind it well.
Transfer the ground batter into a bowl. In a tadka pan, heat 2 tbsp oil, then add 2 tsp mustard seeds, 1 tsp cumin seeds, a pinch of hing, some chopped curry leaves, 1 tbsp chopped green chili, 1 tsp grated ginger, and ½ cup chopped onion. Sauté well.
Add the tempering to the batter and mix in some chopped coriander leaves. Mix well.
The Dahi Vadi batter is now ready.
In a pressure cooker, add some water and bring it to a boil. Place a ring in the center, then place the bowl of Dahi Vadi batter on top and cover it with a plate.
Cover the lid and pressure cook the batter on low flame for 5 whistles.
Turn off the gas and allow the pressure cooker to release pressure naturally. Do not let it cool for too long.
Open the lid, remove the bowl from the cooker, and whisk the hot, cooked batter in one direction for 1–2 minutes. Add some oil and mix well into the batter.
Once the batter becomes smooth, spread a small amount on a plate and try rolling it. If it rolls properly, pour the hot batter onto a greased plate.
Sprinkle some sesame seeds on top and let it cool completely.
Cut the Dahi Vadi into small, thin squares and serve with oil and dry garlic chutney.