Stir in zucchini and salt. Simmer 5 minutes. Transfer meat mixture to a shallow 1 quart baking dish. Put cornbread mix, egg and milk in a medium bowl. Stir until blended, but with some lumps remaining.
Drop tablespoonfuls around edge of baking dish, leaving center uncovered.
Sprinkle cornbread batter with corn and cheese. Bake 20 minutes or until a wooden pick inserted in cornbread comes out clean.