Gently flatten the fish fillets using the flat side of a wide knife. Season with salt and pepper.
Peel the skin from the tomatoes and cut into pieces.
Peel the garlic clove, then blend the tomatoes and garlic in a food processor at high speed. Pass through a fine sieve to extract the juice.
Wash and slice the leeks. Blanch for 5 minutes in boiling salted water, drain, then sweat in 2 knobs of butter over low heat, covered, for about 10 minutes. Season to taste.
Place a portion of leek fondue at the base of each fillet and roll into paupiettes. Secure with cocktail sticks.
Bring the tomato juice to a simmer in a sauté pan. Poach the paupiettes for 2 minutes per side, then remove delicately and keep warm.
Cook the pasta nests in 3 liters of boiling salted water for about 9 minutes. Drain, toss with 2 knobs of butter, and season with pepper.
Arrange the rolls in a ring on four plates, with the pasta nests in the center.
Finish the sauce by whisking in the remaining butter pieces off the heat. Adjust seasoning, then drizzle over the paupiettes, avoiding the pasta.
Recipe by Chef Hubert, a master of French fine dining with over 30 years of expertise in seafood preparations.
