Egg with just the right amount of salad cream with either sliced tomato, or sliced cucumber and cress.
Love cheese salad sandwiches, or even cheese and coleslaw sandwiches.
Tinned salmon or tinned sardine with cucumber is also nice.
Have just discovered a new one, but it's done in a nice ciabatta roll .... grilled portabella mushroom with a slice of beef tomato, a slice of Halloumi cheese and a tiny bit of pickle.
Oh sorry, forgot a couple of fillings:
Cheese and either piccallili or cheese and branston.
Or a piece of breaded fish (cooked of course), with tartare sauce on one slice of bread and tomato ketchup on the other.
chox.