Toast the fennel and coriander seeds in a dry small skillet over medium heat until fragrant. Transfer to a bowl and add the juniper berries, sugar, salt and orange and lemon zests.
Place the salmon, skin side down, on a large sheet of parchment paper set on a large rimmed baking sheet. Pack the spice cure on the flesh side of the salmon, pressing so it adheres.
Toss the beets and chopped dill in a medium bowl and combine. Spread this onto the flesh side of fish and again press. Fold the sides of the parchment over the salmon and then wrap it tightly in plastic wrap. Set another baking sheet on top of salmon and weight it with three 28-oz. cans or the equivalent in cookbooks or other heavy things you have in your kitchen. Refrigerate for 24 to 48 hours before slicing and serving.