In a mixing bowl, combine the salt, sugar, and cracked black pepper and mix thoroughly. Set aside.

Place half of the dill sprigs along the bottom of a glass or other nonreactive container large enough to hold the salmon in 1 layer. Place the salmon, skin side down, on top of the dill, then cover the entire salmon with the salt mixture, packing the cure into the salmon. Cover the fish with the remaining dill sprigs. Cover tightly with plastic wrap and place something heavy such as a skillet, weights, or a brick (which needs to be wrapped in plastic wrap), on top of the salmon. Refrigerate the salmon for 24 to 36 hours, turning occasionally to ensure even curing.

Remove the salmon from the refrigerator and wipe off the curing mixture. Using a sharp knife, slice the salmon from the skin, cutting diagonally and making cuts as paper thin as possible. Serve with crispbread, rye crackers or pumpernickel bread, and Mustard Sauce for Gravlax.

Note: Gravlax will keep, refrigerated for several days if wrapped in plastic wrap. For best results, remove as much of the cure from the salmon as possible once it has cured to the desired degree.

Mustard-Dill Sauce for Gravlax:

Combine mustard, sugar, vinegar, salt, and pepper in a large bowl and whisk to dissolve the sugar. While continuing to whisk, add the oil in a thin, steady stream until completely incorporated and emulsified. Stir in the dill and adjust seasoning, to taste.