In the town I grew up in, there's this great little sandwich shop called San Benito. The bake their own bread and it's heaven. One of their most famous sandwiches is a little cheddar and avocado number. Here's my at home version...it's not even close to the original, but I live 3,000 miles away now and this substitution gets me through the days.
Avocado and Cheddar Sandwich
Whole wheat bread
Sharp Cheddar cheese
Salt & pepper
Lettuce, tomato, sprouts (optional)
Multi-grain bread with seeds is the best for this, but I usually only have whole wheat on hand. It's good enough.
Spread both pieces of bread with a thin layer of mayonnaise.
Layer on slices of the sharpest Cheddar you can find. (I like Irish Cheddar or extra sharp.)
Lay slices of soft, ripe avocado over the cheese. Sprinkle the avocado with salt and pepper.
At this point, you can add lettuce, tomato, or sprouts, but I pass on it. Top with your other piece of bread and get ready for bliss.
I know this is a high fat sandwich, but it keeps you full for a long time and they're healthy fats, so I think it's ok every once in awhile.