Cut the salmon into 4 big pieces.
Rub salt and pepper and let it rest for about 5 minutes.
While the salmon rests, grate the skin of lemon and orange and keep the zest ready.
Also, squeeze out the juice from one lemon.
Then, heat butter in a grill pan. Spread it evenly.
When the butter starts changing its colour, place the salmon pieces on the pan.
On high heat, pan-fry them for about 5-6 minutes.
Add lemon zest. Fry for 2 minutes.
Add lemon juice. Fry for 2 minutes more.
Remove from the pan. Pour the lemon-butter sauce on top. Garnish with chopped coriander/parsley and sliced oranges/lemon and serve.