Cut the avocado in half lengthwise and remove the pit. Scoop out the flesh from the skin and place it on a cutting board. Then halve the lemon.
Lay the two slices of rye bread flat on the counter. Distribute the avocado pieces over the bread and mash the flesh with a firm fork until both slices are evenly covered with a thick layer.
Divide the hundred grams of smoked salmon into equal portions and place the slices directly on the mashed avocado. Squeeze the lemon half firmly over the fish and finally scatter the capers over everything.
Transfer the prepared slices of rye bread to a plate. Serve the dish immediately so the bread retains its firm structure and doesn't become soft from the moisture.