Rinse potatoes and cut flat at one end. Place potatoes with the flattened end on a board. Gently pat fillets between plastic wrap. Wrap each potato with a fish fillet (skinned side inside), secure with toothpicks. (The rolls keep the shape and fill more easily.) Preheat oven to 60 degrees to keep warm.
2. bring to a boil about 1 liter of water with onion, vermouth, wine, bay spice, a few peppercorns and herb stems and season with salt.
Place the fish rolls in the broth and simmer with the lid closed for about 10 minutes more than make. ! In the meantime, prepare the saffron long grain rice.
3. lift rolls out of stock, remove wooden sticks, gently squeeze out potatoes. Cover the rolls with cling film and keep warm in the oven.
For the sauce, boil 125 ml of the cooking stock to half, mix in crème fraîche. Boil sauce until creamy, pour through a fine sieve, add cold pieces of butter and tarragon and blend finely with a hand blender. Stir in shrimp and warm in the sauce, season with salt, pepper and a few drops of juice of a lemon.
5. fill sole rolls with shrimp ragout, drizzle with remaining sauce and bring to table with the asparagus saffron long grain rice.
Asparagus saffron long grain rice:
Rinse long grain rice in a colander until cooled and drain. Peel bottom third of asparagus spears, cut away woody ends. Asparagus tips 3¿4 cm long