How to Make It
Chop 4 of the carrots into 1/2-inch pieces. In a medium saucepan of salted boiling water, cook the chopped carrots until tender, about 15 minutes. Drain well. Transfer the carrots to a blender, add the butter and sesame oil and puree until smooth; season with salt and pepper and keep warm.
Meanwhile, in a small skillet, toast the sesame seeds over low heat, stirring, until fragrant, 2 minutes. Transfer to a plate.
Using a vegetable peeler, shave the remaining 2 carrots lengthwise into ribbons. In a medium bowl, toss the carrot ribbons with the olive oil, lemon juice and ginger and season with salt and pepper.
Season the sea bass with salt and pepper and arrange in a steamer basket set in a saucepan over simmering water. Cover and steam until just white throughout, 4 to 5 minutes.
Meanwhile, in a small skillet, heat 1/8 inch of canola oil. Add the carrot tops and fry over moderate heat until deep green, 1 to 2 minutes. Transfer to a paper towel–lined plate to drain; the carrot tops will crisp as they cool.
Spread the carrot puree on plates; top with the steamed fish and carrot salad. Garnish with the sesame seeds, fried carrot tops, scallion and orange zest. Sprinkle with fleur de sel and pepper and serve.