-crushed Cut the salmon in half lengthwise and remove the backbone and the small, freebones, as well, or ask your fish dealer to do it for you. Leave the skin on. Place half of the fish, skin side down, in a deep glass, enamel or stainless steel baking dish or casserole. Wash and then shake dry the bunch of dill and place it on the fish. (If the dill is of the hothouse variety and not very pungent, chop the herb coarsely to release it's flavor and sprinkle it over the fish instead.) In a separate bowl, combine the salt, sugar and crushed peppercorns. Sprinkle this mixture evenly over the dill. Top with the other half of the fish, skin side up. Cover with foil and set a heavy plate or platter on top of it, slightly larger than the salmon. Weigh it down with cans or jars and refrigerate for at least 3 days, up to 7 days. Turn the fish over every dozen hours or so, basting with the liquid marinade that accumulates, separating the halves a little to baste the salmon inside. Replace the platter and weights each time. When the gravlax is finished, remove the fish