Here's an easy method for wet-brining salmon fillets that ensures even, never salty curing. We wanted an easy gravlax recipe for evenly moist and tender salmon that was consistently salted throughout. A wet brine in red onion juice ensured that the salt and other curing ingredients were evenly distributed throughout the salmon fillet, producing a moist gravlax recipe with great texture. The procedure was simple enough: We skinned the salmon and placed the fillet and curing ingredients in a zipper-lock bag, thereby maximizing brine penetration and eliminating the need to flip the fillet. All the fish needed was to be weighted down and refrigerated for 12 to 18 hours (depending on thickness).