Combine the sugar and salt and mix well. In a 2” steam table pan, spread 2 cups of the sugar mixture as a base. Place the salmon fillet skin side down onto the salt mixture. Cover the salmon with 2 more cups of the salt mixture.
Combine the fennel, parsley, tarragon, fennel seeds, pepper, and zests and scatter over the salmon. over the fennel mixture with remaining 2 cups of salt mixture. Cover with plastic wrap and place a hotel pan on top. Weight the hotel pan with a #10 can. Cure in refrigerator 24 hours.
After 24 hours, pour off any liquid that may accumulate, flip salmon over, recover with cure mixture, cover with plastic wrap, replace pan and weight, and cure another 24 hours. Remove salmon from cure, rinse, dry, and cover flesh side with minced fennel fronds. Refrigerate 24 hours before serving.
Prepare egg poaching liquid by bringing to a bare simmer 2 quarts of water and 2 Tbsp. of vinegar. Slice the salmon thinly and lay slices on plastic wrap lined sheet pan. Cover with plastic wrap and reserve. You will need 2 oz. per portion. In a 400°F oven, place the dry asparagus. Bake for 3-4 minutes until barley tender.
While asparagus is baking, toast the bread slices. While bread and asparagus are cooking, poach each egg until the whites are just set.
Place the bread slices in the center of 4 plates. Top with 2 asparagus spears, 2 oz. of sliced salmon and top with warm poached egg. Season with salt and white pepper and serve immediately.