Combine in bowl grated beets, sea salt, sugar, crushed peppercorns and lemon zest. Mix well to create curing mixture. Place large piece of plastic wrap on clean surface. Spread half the curing mixture on plastic wrap, creating a bed for salmon.
Lay salmon filets, skin side down, atop curing mixture. Make sure filets are evenly spaced and not touching each other. Completely cover top and sides of salmon with remaining curing mixture. Wrap salmon tightly with plastic wrap, ensuring there are no air pockets. Place wrapped salmon in large dish or baking sheet to catch any liquid that may seep out during curing. Place a weight like a heavy can or plate on top of wrapped salmon to help to press salmon and aid in curing process. Transfer dish to refrigerator and let salmon cure for 48 hours. Longer curing increases firmness and flavor.
After curing time has passed, unwrap salmon and rinse off curing mixture under cold water. Pat salmon dry with paper towels. Slice salmon thinly against the grain, removing skin if desired. Garnish with fresh dill.
