I made this for a dinner party and I have to say, it was a real hit. Be sure to use a good brand of mayonnaise that has a lot of "egg" (I like Trader Joe's brand). I did make a few modifications: used Jack Cheese rather than Mozzarella and I didn't use a cover but, rather, just put it into a shallow dish and baked it. Plus, I served it on thin, fresh slices of baguette. Very nice.