FISH Fillets: Season fillets with salt and pepper. Refrigerate on resting rack until needed. Combine coriander, fennel seed, cardamom, mustard seed and orange zest in spice grinder; grind to a coarse consistency. Set aside.
RHUBARB-MUSTARD Jam: Place juices, honey, bay leaves and thyme in saucepan; cook on medium heat until about 1/4 of the liquid remains. Add rhubarb; cook until heated through. Stir in mustard; season with salt and pepper to taste.
SPRING Vegetables & Quinoa Salad: Blanch fiddlehead ferns in boiling salted water just until slightly tender. Remove from heat; shock in ice water until cooled. Set aside to dry. Mix mustard and grapeseed oil; season with salt and pepper. Set aside. Toss onions, mushrooms and blanched fiddleheads with a drizzle of grapeseed oil to coat. Season with salt and pepper.
TOSS grilled vegetables in bowl with greens and thyme; season with salt and pepper. Stir in quinoa. Add mustard mixture; mix lightly.
FOR each serving: Spread 1/2 Tbsp. country Dijon mustard evenly across flesh side of 1 fish fillet; place, mustard side down, on hot oiled grill. Once fish releases from grill grates, rotate 90 degrees to give cross-hatch marks. Repeat on other side. Place fillet on sizzle plate, mustard side up; sprinkle with 1/2 tsp. coriander mixture. Finish cooking in 350ºF standard oven just until cooked to desired doneness.
SPOON 1/2 cup Rhubarb-Mustard Jam across plate. Place about 1/2 cup Spring Vegetables & Quinoa Salad in a line crossing the jam at a slight angle; top with fish fillet.