Grind the oats.
Grate the ginger and keep it aside.
Put the oats powder in a bowl. Add semolina, curd, salt and grated ginger to it. Mix it. If the consistency is thick, add some water. Keep it aside for half an hour.
Grease a pan, put water in the steamer, lit the stove.
Put baking soda to the batter, mix and pour it immediately to the greased bowl.
Steam it for 10-12 minutes. The best way to check if it is done properly, is to insert a knife, if it comes out clean, it is done.Keep it aside.
Make the seasoning. Heat oil in a pan, add mustard seeds, as it crackles, put sesame. Throw in the green chilly and curry leaves. Put the tempering over the prepared dhokla and cut into pieces.