Avocado sandwich, well, you can either just slice them and put them with cheese (provolone works well), tomato, onion, cucumber on your favorite roll or bread. Some folks add sprouts and lettuce or mash the avocado up with some lemon and spices first. Or something I like to do is get some nice sourdough or rye, butter it, put some provolone or mild cheddar on both sides of bread, avocado on top, assemble sandwich and fry in a skillet until crunch on the outside and melty and yummy inside. There is a restaurant here that makes one with Tomato, onions, and Swiss cheese with an avocado and cashew spread that I really like.