Break noodles in half. Cook noodles, reserving flavour sachets, in a small saucepan of boiling water for 3 minutes or until just tender. Drain.
Combine cornflour, eggs and reserved sachets in a large bowl. Add corn, white part of onion, cabbage and noodles, then stir to combine.
Heat oil in a 24cm (base measurement) frying pan over medium heat. Add noodle mixture to pan, flattening slightly with a spatula. Cook for 3 minutes or until golden and set. When pancake has set and is firm enough to turn, carefully turn over (see Tip). Cook pancake for a further 3 minutes or until cooked and hot.
Transfer pancake to a plate. Top with mayonnaise and green part of onion.