Cook corn and drain well.

In a large bowl, combine cooked corn, evaporated milk, beaten egg, finely chopped onion, salt, and 3/4 cup shredded Swiss cheese.

Transfer the mixture to a 1 1/2-quart greased baking dish.

In a separate small bowl, toss bread crumbs with melted margarine and 1/4 cup Swiss cheese.

Sprinkle the bread crumb mixture evenly over the corn mixture in the baking dish.

Bake in a moderate oven (350°F/175°C) for 25 to 30 minutes, or until golden brown and bubbly.

If desired, garnish with green pepper rings before serving.