Gruyere Swiss cheese adds a wonderful nutty sophistication to this simple dish. Gruyere is on the expensive side, but you don't end up needing as much because the flavor is more concentrated. You can substitute another Swiss cheese if you like. The trick to keeping the zucchini from getting soggy and overcooked, is to sauté it quickly in a rather hot pan.
Harissa is a traditional accompaniment with Moroccan and North African food. Use sparingly as it is powerfully HOT. It is a great with lamb chops, chicken and vegetarian dishes and as a flavour base for any casseroles or stews where a fresh zing is needed.