Arrange zucchini slices in the bottom of a 1-quart casserole.
Mix parmesan cheese, basil and salt together.
Sprinkle over zucchini.
Place butter in custard cup.
Microwave on HIGH until butter melts.
Drizzle over top of zucchini.
Microwave 4 to 5 minutes on HIGH, or until zucchini is tender crisp.