Clean and wash the prawns well. Drain out all the water.
Chop the onion and capsicum finely.
In a wok, heat 3 tbsp oil. Add in the onions and fry till translucent.
Add in the prawns and fry till half cooked.
Add in 1 tsp pepper powder, 1 tsp cumin powder, ½ tsp turmeric powder, ¼ tsp salt, juice of half a lime, around ¼ cup water and the chopped capsicum. Mix well and cook till the prawns are fully cooked.