Marinate shrimp with turmeric, chilli powder and lime juice for 20 minutes. Fry in a bit of oil till crisp on both sides. Set aside.
Heat remaining oil and saute ginger till fragrant. Add onions and fry for a few minutes till tender and pink.
Add in chilli flakes, salt, tomato paste and soy sauce, and stir-fry for a few minutes till it starts to give out oil from the sides. Add shrimp, and stir fry for a minute or two blending spices well.
Garnish with chopped green onions and serve alongside plain rice and a large pitcher of ice-cold water.