Remove small bones from salmon with tweezers; discard bones.
Stir together sugar and next 3 ingredients. Pour one-third of the mixture in a 13- x 9-inch baking dish. Place salmon fillet over sugar mixture, and top with remaining sugar mixture. Cover with heavy-duty plastic wrap. Place an 11- x 7-inch baking dish over salmon. Fill with heavy cans. Let stand 2 hours at room temperature. Remove weights and smaller dish; pour off liquid. Cover with heavy-duty plastic wrap; chill for 2 days.
Rinse coating from salmon; pat dry. Slice thinly, starting at tail end. Serve on toasted baguette slices with Cilantro-Mustard Sauce. Garnish, if desired.
Note: For toasted baguette slices, cut baguette into 1/4-inch slices, and place on a baking sheet. Bake at 350º for 3 to 4 minutes on each side or until lightly browned. Cool on wire racks.