Cut lemon in half. Squeeze juice from lemon into a 3-qt. saucepan. Add lemon halves, 2 Tbsp. salt, and 6 cups water, and bring to a boil over medium-high heat. Add salmon fillet (cut into 2 pieces, if necessary); cover and reduce heat to low. Simmer 4 minutes. (Center of salmon will be raw.) Carefully transfer salmon to a large bowl, and cool completely (about 10 minutes). Remove and discard skin, and flake salmon.
Preheat oven to 425°. Stir 1/2 cup panko and next 11 ingredients into flaked salmon.
Stir together melted butter and remaining 2 cups panko. Spoon 1 tsp. panko mixture into each cup of a lightly greased 24-cup miniature muffin pan. Add 1 Tbsp. salmon mixture to each muffin cup. Top each with 1 tsp. panko mixture.
Bake, in batches, at 425° for 10 minutes or until topping is golden brown. Serve warm with Ginger Rémoulade.
We tested with McCormick Gourmet Collection Toasted Sesame Seed.
Total time does not include Ginger Rémoulade.
Make Ahead: Prepare recipe as directed. Cool completely, and freeze in zip-top plastic bags. Bake at 350° for 10 to 15 minutes or until warm.