Thaw the fish thoroughly, still in the vacuum bag, in very cold water. When completely thawed, place the fish on a paper towel to remove excess moisture
Place a cup of all-purpose flour on a plate and spread it well. Place the fillets in flour, coat both sides well and gently shake the fillets over the plate to remove excess. Set aside
Cut the butternut squash in half, remove the seeds and microwave for about 4 to 5 minutes on high temperature. When tender, scrape out the inside of the squash and transfer to a bowl, add a tablespoon of salted butter. Season to taste. Set aside
Peel the Nantaise carrots and cut them crosswise on a bevel. In a pan, cook the carrots with salted butter, when they are cooked but still crunchy add 1 tablespoon of maple syrup. Set aside
Preheat skillet to medium-high (8/10) and add 3 tablespoons of olive or vegetable oil. When the temperature is optimal, place the fish fillet in the pan and gently stir two or three times so that the fillet sits well in the pan. Reduce temperature to medium. Cook for about 2 minutes per side to get a nice coloration. To ensure perfect cooking, press gently with the back of a spoon on the fish, if the flesh flakes off, it is ready
Reheat the purée and the Nantaise carrots, place first the purée, then the turbot fillet, finish with the carrots and radish sprouts