Combine rice and stock in a large saucepan and bring to boil. Cover and simmer for 10 minutes, until par-cooked.
Lay out eight 20cm-squares of baking paper or foil squares and place a strip of banana leaf in centre of each. Top with ½ cup of rice, capsicum, ginger, green onion and coriander. Fold banana leaf over filling and wrap in baking paper to enclose. Tie with string. Steam over simmering water for 10 minutes. Open and serve with soy sauce.