Jumbo Prawns with Sweet and Sour Glaze

Cut the prawns from the back, keep the shells on and remove the vein. Pat the prawns dry with a paper towel.
Finely chop the ginger, lemon grass, garlic and scallion. Mix the cornstarch and water in a small cup and set aside.

Heat some oil over medium high heat and sauté the ginger and lemon grass then cook until fragrant.
Add shrimp and cook for about 2 minutes on each side. Add in the ketchup, sugar and chili sauce. Zest half the lemon and add all the juice and cook until the sauce is reduced slightly. Thicken the sauce with the cornstarch and water mix. Sprinkle with chopped scallions. Check the seasoning and when it's ready to serve garnish with cilantro sprigs.