Blend onion, ginger, and garlic with 2 tablespoons water. Remove, pour into a small bowl. Mix with curry powder and chili powder to form a paste.
In a medium sized pot, heat vegetable oil. Add curry paste and curry leaves and stir for 5 minutes until fragrant.
Pour in coconut milk. Bring to a boil, season with salt and tamarind paste. Add eggplants and jalapeno, reduce heat and let simmer for 5 minutes.
Add shrimp and tomatoes and continue to cook for another 3 to 4 minutes until shrimps curl. Turn off heat and let curry sit for 10 minutes before serving.