Steamed Tiger Prawns with Garlic (蒜茸蒸虎蝦)

Ingredients:

10 tiger prawns
3 tbsp ground garlic
2 tbsp ground ginger
1 tbsp finely chopped green onion
1 tsp sugar
A quarter tsp salt
Half tsp white pepper powder
1 tsp cooking wine
2 tbsp soy sauce
3 tbsp cooking oil