Be sure to precisely measure the salt amount and not to exceed the brining time, otherwise the final result may be too salty.
Keep the serving plates in the oven at the lowest setting so they are warm when you serve.
Pour the water and salt in a bowl or shallow mould, then mix well until the salt is dissolved. Lightly crush the peppercorns then add them to the brine. Add the grated zest and maple syrup.
Remove and discard the skin of the salmon, then put the salmon in the brine. Cover the salmon completely with the brine (Depending on the size of the bowl, it may be necessary to add some additional brine to cover the salmon: you will need 1 tablespoon of salt for every cup of water). Cover and chill in the refrigerator for at least 4 h (maximum overnight).
Take the salmon out of the brine, pat it dry using paper towels, then cut it into serving size pieces. Discard the brine.
Heat the oil in a nonstick pan over medium heat. Sear the salmon, 2 min per side, until a light gold crust is formed. Lower the heat to 'low' and cook an additional 4-5 min. Check with a fork to see if the fish is cooked through. Serve on the warmed plates.