My husband and I have these about twice a week and after we eat them, we fantasize about opening up a sandwich cart and only serving the best sandwiches.
The toppings tend to change based on what we have in the house but below is a favorite combination:
sourdough toasted bread
Other optional ingredients:
fried egg - I do that for my husband
pretty much anything that is tasty on a sandwich should go on here.
I love these so much and I would make them every morning if avocados didn't cost so much and I need a bit more variety in my diet.