Marinate the cleaned prawns with ginger garlic paste, turmeric powder, Kashmiri chilli powder, pepper powder, fennel powder, fennel seeds, cornflour, vinegar and salt. Keep it aside for half - one hour.
Heat oil in a wide pan, add the finely chopped garlic, when it begins to brown, add green chillies and curry leaves. When it becomes golden brown, transfer it to a plate.
To the same pan (add more oil, if required) add marinated prawns. Cook till it's one and both sides become golden. Keep in mind, prawns cook fast and overcooking will turn it rubbery.
Add the fried garlic, green chillies and curry leaves to the cooked prawns. Toss it so that it's combined well. Transfer to a serving plate. Serve hot.
Notes
You can serve this as an appetizer or a side for rice. We had it as an appetizer and had chili mayo as a dip.If planning to serve as an appetizer, it's better to use medium-big size prawns.You can make it a veggie version with potatoes/mushroom/cauliflower. For potatoes, I think parboiled potatoes work best.