Michel Bourdin created this dish in honor of Queen Elizabeth II, in celebration of the Silver Jubilee of her reign, in 1977.
FOR THE DUXELLES:
8 oz. white mushrooms, trimmed and minced
3 tbsp. butter
4 shallots, peeled and minced
1 oz. fresh wild mushrooms, trimmed and minced
1/2 cup heavy cream
Salt and freshly ground black pepper
FOR THE SOLE:
4 8–10-oz. dover soles, cleaned and
skinned, heads and tails removed
3 cups dry white wine
8 cups fish stock
12 sprigs fresh parsley
6 sprigs fresh thyme
6 white mushrooms, sliced
4 shallots, peeled and sliced
8 tbsp. butter, cut into pieces
2 tsp. whole black peppercorns
2 lbs. frozen puff pastry, thawed
1 egg, well beaten
2 cups heavy cream
Salt and freshly ground white pepper
1 tsp. chopped fresh parsley
1 tsp. chopped fresh chervil
1. For the duxelles: Put white mushrooms into the center of a clean dish towel and twist towel to squeeze out all moisture. Meanwhile, melt 1 tbsp. of the butter in a medium skillet over medium-high heat and sauté one-quarter of the shallots for 1 minute. Add white mushrooms and sauté, stirring often, until skillet is dry, about 8 minutes. Transfer to a bowl and set aside. Return skillet to medium heat, melt remaining 2 tbsp. butter, add remaining shallots, and cook, stirring often, until soft, 4–5 minutes. Add wild mushrooms and cook, stirring often, until soft, 3–4 minutes. Add cream and bring to a boil. Reduce heat to medium-low and simmer, stirring often, until thick, 5–6 minutes. Add reserved mushrooms, season to taste with salt and pepper, and set aside.
2. For the sole: Arrange fish in a roasting pan. Add half the wine, stock, parsley sprigs, thyme, mushrooms, shallots, butter, and peppercorns. Poach over medium-low heat until fish is just cooked, 12–15 minutes. Transfer fish to a clean surface and let cool, reserving liquid. Keeping bottom filets intact, halve top filets lengthwise, then carefully debone fish. Mound one-quarter of the duxelles in the center of each filet bottom. Cover each with top filet pieces. Using a 4''-long oval pastry cutter, cut out each stuffed filet into an oval and set trimmings aside. Roll out puff pastry to 1/8'' thickness and cut out four 6'' rounds and four 5'' ovals. Place rounds on a parchment-lined baking sheet, center stuffed filets on each round, cover with oval pieces (decorated, if you like), and seal edges. Brush tops with egg wash and refrigerate.
3. Put bones and trimmings, poaching liquid, remaining wine, stock, parsley, thyme, mushrooms, and shallots into a saucepan. Simmer over medium heat until reduced to a thick syrup, 3 hours. Add cream and simmer until reduced by half, 15 minutes. Strain through a fine sieve and season to taste with salt and pepper. Keep warm over low heat.
4. Preheat oven to 425º. Bake pastry until golden, about 20 minutes. Add parsley and chervil to sauce and pour around each pastry.