For the salmon: Place the salmon in a 9-by-13-inch baking dish, skin side down. Blend the fennel seeds, dill seeds, black peppercorns and coriander seeds in a spice grinder. Mix the salt, sugar and ground spices in a small bowl and rub them over the top of the salmon. Cover the salmon with the dill, and then wrap the salmon dish in plastic and refrigerate. Leave the salmon in the refrigerator for 2 days to cure.
For the fennel: Wash the fennel in cold water and remove the top stalks. Cut the bulb in half through the stem, and then slice the bulb halves on a mandoline into a bowl of ice water. Pick the fennel dill (the top of the fennel) into the ice water with the fennel slices.
For the raeve sauce: Whisk to combine the Dijon mustard, grainy mustard, brown sugar and dill in a medium bowl. Whisk until the sugar crystals are dissolved, about 1 minute.
For the croutons: Tear the rye bread into 1/2-inch pieces. Melt the butter in a small pot and add the bread pieces. Toast, stirring occasionally, until the butter is brown and the croutons are crispy, 5 to 7 minutes. Remove from the pot and drain on a towel-lined plate.
Remove the fennel and fennel fronds from the ice water and drain on a towel to dry. Place in a medium bowl and toss to combine with the watercress, salt and pepper.
Use a chef's knife to slice the gravad lax into a 3 1/2-ounce portion per person. Plate and top with 1 tablespoon reeve sauce, 5 to 6 rye croutons and 2 tablespoons fennel and watercress salad.
Copyright 2020 Television Food Network, G.P. All rights reserved.