Wash and soak sago for 10 minutes; drain well and set aside.
Cut banana leaves into 20 x 15cm pieces. Soften the banana leaves in boiling water for 30-40 seconds. Remove and wipe dry.
Combine plain and hoen kwe flour, sugar, salt and coconut milk in a mixing bowl. Add sago and sweet corn kernels and mix to form a thick batter. Place 2½ tablespoons of batter on a piece of banana leaf. Level it and fold to form a packet. Steam over a medium flame for 10 minutes. Serve the kuih immediately.