thin spaghetti noodles
1/2 lb large prawns (16-20 size) peeled and deveined
1 tbs oyster sauce
1/2 ts salt
1/2 ts sugar
1 ts pepper
3 tbs garlic, finely minced
3 tbs French buerre demi sel, divided in 3rds
1 green onion, chopped 1 inch pieces
freshly grated parmesan cheese (optional)