Add semolina, yogurt, chopped onion, chopped ginger and salt in a bowl.
Add water to make a batter of desired consistency. Keep the mixture aside.
For tempering heat 2 tsp oil in a pan. Add mustard seeds and urad dal. When mustard seeds splutter add curry leaves, dry red chillies & asafoetida. Add this tempering to the semolina.
Add some water to adjust the consisitency of batter.
Heat the appe mould on a medium flame and grease it lightly with oil.
Add Eno Fruit Salt alongwith 1 tablespoon of water in the batter and mix it well.
Immediately pour a spoonful of the batter into each mould and cook it till the outer surface becomes golden brown.
Turn each appe upside down using a fork to cook from the other side.
Repeat with the remaining batter to make more appes.