In a mixing bowl, add 2 cups of fermented batter. Add 1 cup grated lauki, ½ cup chopped coriander leaves, 1 tbsp green chilli-ginger paste, 1 tbsp crushed peanuts, ½ tsp turmeric powder, salt to taste, 1 tsp red chilli powder, and 1 tsp sugar. Mix well.
In a tadka pan, heat 1 tbsp oil. Add ½ tsp mustard seeds, ½ tsp cumin seeds, 1 tsp sesame seeds, some curry leaves, a pinch of hing, and 2 dry red chillies. Sauté well.
Add ½ tsp baking soda into the batter, then pour the hot tadka over it. Mix well. The batter is ready.
In a kadai, heat 2 tbsp oil and sprinkle some sesame seeds.
Add 2 ladles of handvo batter and spread it slightly.
Cover and cook the handvo on medium-low flame for 10–12 minutes until it becomes crispy from both sides.
Serve handvo with green chutney or tomato ketchup.