- In a small bowl, combine the maple sugar and salt. Set aside.
- Place the fish steaks on a plate. On a second plate, place the leek greens. Rub half of the sugar mixture onto the fish, and sprinkle the remaining sugar mixture over the leeks. Refrigerate for 45 minutes. Pat dry, if needed. Let rest at room temperature for 15 minutes.
- With the rack in the middle position, preheat the oven to 230°F (110°C).
- In a lightly oiled 11 x 8-inch (28 x 20 cm) glass baking dish, spread the leek greens in a thin layer. Place the fish on the leeks. Brush the steaks with 1 tbsp (15 ml) of the oil.
- Bake for 20 to 25 minutes, depending on the thickness of the fish, or until the flesh detaches easily from the skin. Let cool. Remove the skin and set the fish aside on a plate.
- In a large bowl, combine the remaining oil (2 tbsp/30 ml) with the cider vinegar, maple syrup, leek whites, radishes and cucumbers. Season with salt.
- Spread the crème fraîche onto plates. Top with the leek confit, fish and vegetables.