Its a cheap fast food, mostly famous in the south. The name "Soosis Bandari" means that it is a style of sausages as made in Bandar Abbas.
Personally, I loooove it. The way we make it in the south (or at home) is to make it super spicy.
This is our style, if you want to make it at home.
Slice onions. Put them in a lot of oil to fry. Slice sausages, and add them to the frying pan. Add tomatoes paste and lots of red spices. That's it. Some like to first fry potatoes (cubed into small pieces) instead of the onions, but the onion version is used more.
Anyway, then add them to sandwich bread, and add these three toppings:
1) Mince pickled cucumbers into very small pieces and mix it with mayonnaise
2) Use fresh basil
3) Spicy ketchup or hot sauce
I desperately want some soosis bandari now. I bet in India, they make it spicy the way I like them, but in Tehran, they don't make it spicy, so when I visit my hometown, I HAVE to eat them. Also, my wife sometimes makes it for me, but not too much, because its unhealthy and I eat a lot of it.