@GaryPoole Lots is my answer. And buttered bread, none of that mayonnaise on t he outside. (I tried it reading people extolling the virtues amd superiority to butter. Negative. Not the same taste.)
I like very sharp cheddar but anything will do in a pinch.
@S_r_stone
Completely agree. Sure, the mayo gives a nice even browning... but it doesn't *taste* as lovely as butter.
@GaryPoole