When I became vegetarian, i missed the weirdest things, and one of those things was chicken and tuna salad sandwiches. This is a good substitute, because with the mustard, mayonnaise, and relish, you can hardly tell what the main ingredient is anyway. Non-vegetarians will like it too!
Put the chickpeas, mustard, mayonnaise, and pickle relish (or whatever you would typically make meat salads with) in a bowl and mash with a fork into a lumpy consistency (should have texture, not smooth like hummous). Put cheese on one slice of vegan bread spoon chickpea salad over it. Top with lettuce and tomato slices and add pepper to taste. Put other slice of bread on top to close sandwich and slice in half from corner to corner. Yummy... enjoy! ;)