Slit each bitter gourd, remove seeds, without washing marinate with 1 tsp turmeric, 1 tbsp jaggery and a pinch of salt for 20 minutes. Then wash well. Heat 1 cup oil in pan, add in 4 chopped onion and fry till its color turn to light pink. Add in 1 tsp turmeric, 1 tbsp chili powder, 2 raw mango, 1 tsp onion seeds, 1 tbsp ginger garlic paste and salt to taste. Slightly fry and remove. Fill this mixture in bitter gourd. Roll with string to seal. Shallow fry in frying pan with oil as required. Put stuffed bitter gourd in remaining Masala. Add in 1 tbsp jaggery, 4 chopped green chilies, 6 to 7 curry leaves and salt to taste. Simmer on low flame for 10 minutes till done.