Salmon baked in sea salt crust with crab and spinach stuffing

1 Whole Salmon (8-10 lbs.), scaled, cleaned, and boned into 2 large filets
Lemon
12 ounces spinach
1-pound lump or Jonah crabmeat
2 tablespoons fresh tarragon (or dill), chopped
6-8 lbs. course sea salt
Directions

Preheat oven to 425 degrees F. Season salmon with salt, pepper, and lemon.
Bring 1 quart of water to boil in large pot. Blanch spinach in hot water and plunge in cold water. Drain well. Lay spinach, crabmeat, and chopped Tarragon or dill on one filet and sandwich by placing the other filet on top. Wrap tightly in cheesecloth and refrigerate for 1-2 hours.
Cover the bottom of a large roasting pan with " layer of sea salt. Place salmon on top of salt. Pile remaining salt all over the fish to cover completely. Spray the surface with a little water.
Bake salmon in hot oven for 20-30 minutes or until cooked. To test if done, use a skewer to pierce through the salt into the thickest part of the fish. If skewer comes out warm, fish is ready.
Break off salt crust gently from the top of fish. The skin will stick to the salt and come away with the crust. Gently lift salmon from the pan, turn over onto a platter, and remove the remaining salt and skin.
Serve with roasted potatoes and root vegetables, such as carrots, parsnips, celery root, and beets. Accompanied by mustard sauce flavored with dill or tarragon.