1. Peel the horseradish. Grate it to yield 2 tablespoons. Mince the parsley.
2. Combine the egg yolks, salt, and water in the bowl of a food processor. With the motor running, gradually add the 1/2 cup each of canola and olive oils (one after the other) to form an emulsion close to the consistency of mayonnaise. Add the lemon juice, then the Worcestershire sauce, the grated horseradish and the parsley. Pulse a few times, until well incorporated. Transfer to a bowl, cover and refrigerate while you cook the fish.
3. Preheat the oven to 400 degrees. Heat a large, ovenproof skillet over medium heat for about 5 minutes or quite hot. Meanwhile, pat the salmon fillets dry with paper towels; season lightly with salt. Dust the fillets with flour on all sides; shake off excess.
4. Add the remaining 2 tablespoons of canola oil to the skillet and swirl to coat. Add the fillets, skin side down. After about 30 seconds, shake the skillet to keep the fillets from sticking (or use a spatula to gently dislodge them). Cook for about 3 minutes, then turn the fillets over. Transfer the skillet to the oven and cook for 6 minutes or until the fish is cooked through but not yet flaky.
5. Serve warm, passing the chilled aioli at the table.
Adapted from In My Kitchen
by Ted Allen (Clarkson Potter)
Per serving (using 4 tablespoons of aioli): 440 calories, 34 g protein, 3 g carbohydrates, 32 g fat, 4 g saturated fat, 120 mg cholesterol, 110 mg sodium, 0 g dietary fiber, 0 g sugar