Put the peppercorns in a spice mill and crush to a coarse grind. In a bowl combine the pepper, sugar and salt and blend well together.
Place the bunches of cilantro, dill, and scallions together in the bowl of a food processor and process until finely chopped.
Rinse some cheese cloth under cold running water. Unfold the cheese cloth and lay a large piece out on your work surface. The cloth will have to be large enough to wrap completely around the salmon several times.
Choose the freshest salmon possible for this dish as this is a cured but not cooked dish and fresh really counts. Cut the fish fillet into two equal pieces and lay it, skin side down, in the center of the cheesecloth. Spread the sugar, salt, and pepper mixture evenly over the salmon flesh. Spread the chopped herbs in the same manner and then sprinkle the tequila over the herbs. The flesh of the salmon should be totally coated in this curing seasoning.
Once all the tequila has been absorbed, sandwich the two fillets together, fleshtoflesh and skinsidesout. Position the fillet "sandwich" in the center of the cloth and wrap as you would a gift, pulling the cloth as tightly as possible around the fillets. Lay the package on a cake cooling rack set over a cookie sheet. The rack allows air to circulate for more efficient drying, while the cookie sheet will catch the liquid extracted during the threeday curing period. Put the weight in a second, smaller cake pan and place it on top of the fish. The weight must be properly and
evenly distributed so as to press out the unwanted water.
Place the entire curing setup in the bottom, the coldest area, of your refrigerator and begin the 3 day curing process. Remove the weight and flip the fish package over every 24 hours, replacing the weight each time. Drain off and discard any liquid that collects in the pan when you do this. At the end of the 72 hours the fish must be cleaned. Remove the cheesecloth and discard it. Drain any accumulated liquid, scrape off all of the used herbs and salt and pepper. Rinse the fish under cold running water and pat the fish totally dry.
The salmon is now fully cured and as entirely edible as smoked salmon but must be kept refrigerated.
To serve, finely chop one cup of fresh cilantro and cover the flesh side of the fish. Using a very sharp knife, slice the salmon as thinly as possible, at a 45 degree angle. Your first slices may look a bit rough, but be patient. With a little practice you'll soon be turning out elegant greenedged red ribbons of gravlax.
Mix the mustard and confectioner's sugar and serve with pumpernickel and wedges of lime.
Weight for weighing down the salmon as it cures, such as unopened plastic bags of dried beans, or gallon jugs of cooking oil .