I got this originally from a collection of DC restaurant recipes, but I've stripped it down to its essentials following suggestions from Mark Bittman's "Minimalist" column.

The original version, from Restaurant Nora, added chopped dill to the curing step and had a tablespoon of cognac in it too. These are unnecessary options, but you can use them or substitute (say) cilantro and tequila, or whatever seems appropriate. See Bittman's column for some interesting variations.

Bittman thinks you can skip the weight and you can, but it firms up the fish and makes slicing it much easier, especially if you bought "previously frozen and thawed for your convenience" salmon at the supermarket.

Gravlax

1 side of salmon (about 2 pounds), skin on
1/4 cup kosher salt
2 tablespoons sugar
2 tablespoons fresh coarsely cracked black peppercorns
1 2-gallon Ziplock bag

Mix the dry ingredients. Put the salmon fillet in the Ziplock bag, rub the salt mixture over the bare surface of the fish (you can forget the skin side; the pickling liquid will work its way there anyway), suck as much air out of the bag as you can, and seal it. Put it in the refrigerator with a suitable weight on it (a brick, a cast-iron pan) and leave it for at least one day but no more than three.

To serve it, remove it from the bag, scrape the salt mixture off, rinse it briefly in cold water and pat it dry. Slice it thinly and serve it with a dill mustard sauce. Serve with a nice stiff bread -- pumpernickel, rye, or Swedish-style crispbread.

The sauce below isn't the recipe I use, but it's very similar.