How to Make It
In a small saucepan of boiling salted water, blanch the scallion greens for 1 minute. Transfer to a bowl of ice water to cool, then pat dry.
Diagonally cut each salmon trout fillet in half to form 2 triangular pieces. Top each piece with a scallion and an apple wedge. Starting from the thin end of the fillet, roll the trout around the apple and scallion. Wrap a bacon slice around each roll and secure with string.
In a nonreactive saucepan, boil the red wine, shallots and rosemary over high heat until reduced to a thick syrup, about 12 minutes. Add the stock and reduce to 3/4 cup, about 5 minutes. Strain and return to the pan. Add the demiglace and bring to a simmer.
Preheat the oven to 350°. Heat a large nonstick skillet. Season the bundles with salt and pepper and set half of them bacon side down in the skillet. Cook over moderately high heat, turning once, until the bacon is browned, about 3 minutes per side. Transfer to a baking sheet and repeat with the remaining bundles. Discard the strings, cover the tournedos with foil and bake for about 4 minutes, or until the fish is firm.
Wipe out the skillet and melt 1/2 tablespoon of the butter in it. Add the mushrooms, season with salt and pepper and cook over high heat until browned on the bottom, about 4 minutes. Stir, then cook until browned all over, about 2 minutes longer. Transfer to a plate. Add the spinach to the skillet and cook until wilted and the excess liquid is evaporated, 3 to 5 minutes. Season with salt and pepper and add the mushrooms.
To serve, reheat the sauce and whisk in the remaining 1 tablespoon butter. Spoon the spinach and mushrooms onto 4 plates. Set 3 tournedos on each spinach mound and spoon the red wine jus around.