one of my favorites as a child was a homemade "bread and butter Pickle" sandwich....munny on home made bread and my mom's bread and butter pickles were the best.
I also like cold left over roast beef sandwiches with plain old ketchup and dill pickles.
grilled ham and cheese with mustard
egg salad on rye or marble rye
turkey, avocado, fresh tomato with miracle whip
peanut butter and banana toast is a go to
bumsters made with spam! grind spam, cheese, a little onion, and a dab of mustard together, spread open faced on a bun half, place under the broiler..until bubbly
sliced cucumbers go great on a lot of sandwiches for a little crunch.
I have been trying to cut out bread but will eat 7 grain bread when I can find it. Lately been using whole wheat or multigrain English muffins as bread...hard now that I am staying out of grocery stores as much as possible.