Wash shrimp in running water, and cut of antennae. Then drain well. In a bowl, mix shrimp thoroughly with sea
salt and 1 tbsp of the sesame oil so that all shrimp are coated with oil.
Bring water of steamer to a boil. Transfer shrimp to a plate and steam for 10-15 minutes or just until pink. Transfer shrimp to a colander to drain. Set aside.
Put cornstarch in a small bowl and gradually add banana sauce to make a paste.
Heat a medium sized wok on medium flame. Add cooking oil, then add garlic, ginger and green chili and stir for about 2 minutes. Add shrimp and toss for 1 minute then pour in banana sauce mixture.
Reduce flame to low, toss shrimp for 2 minutes. then add green onions. Toss before serving.