MUSTARD Veloute: Place butter, onion, peppercorns and chiles in saucepan over low heat; cook about 5 min. or until onions sweat. Add water; simmer 10 min. In bowl, combine creme fraiche and mascarpone cheese until well blended; set aside. Strain liquid from saucepan through chinois to remove solids; discard solids. Return liquid to saucepan over low heat; stir in creme fraiche mixture. Season with salt. Mix cornstarch and water; slowly whisk into saucepan. Continue cooking to thicken slightly. Remove from heat; stir in cream and mustard. Keep warm until ready to serve.
MUSTARD Greens: Cook bacon over low heat in saute pan. Remove bacon from drippings; keep warm. Place greens in pan; stir in salt and pepper. Add water; cover. Cook 10 to 15 min. or until greens are tender, stirring occasionally. Remove from heat; stir in mustard and reserved cooked bacon. Keep warm until ready to serve.
CHIVE Oil: Blend chives, oil and salt in blender or food processor until emulsified. Strain through a chinois; discard solids. Pour into squeeze bottle; set aside for plating.
FOR each serving: Heat 3/4 tsp. oil in medium saute pan over medium-low heat. Cover both sides of 1 fillet with 1 Tbsp. of mustard; season with salt and pepper. Place fish, skin side down, in pan; cook about 10 min. or until fish becomes crispy. Flip fish; finish cooking in 300ºF standard oven for 2 min. Allow to rest in warm place before plating.
PLACE 3/4 cup of hot Mustard Veloute in warmed shallow bowl. Mound 2 oz. of Mustard Greens in center of soup. Drizzle 1 Tbsp. of Chive Oil carefully around Greens. Top with cooked fish, skin side up.