Using a potato peeler, shave the parmesan into thin strips, set to one side.
Mix the olive oil together with the vinegar and some seasoning. Mix into the rocket leaves and place on the plates.
Heat a griddle pan to a high heat. Fold each slice of smoked salmon into three to make one thicker slice. Season with black pepper and drizzle on one side with a little olive oil.
When the pan is very hot, place the salmon on it, oiled side down, and leave for about 15 seconds and then turn a quarter turn and cook for a further 15 seconds and then remove. Do not turn it over, only cook on one side.
Sprinkle the rocket with the parmesan shavings and place the salmon, charred side up, on the top. Serve immediately.