For the cucumber salad:
1. Place the cucumber and red onion in a bowl and toss to combine. Season to taste with lemon juice and salt. Garnish with dill sprigs.
For the salmon and horseradish sauce:
2. Combine the sour cream and horseradish in a small bowl. Season generously with freshly ground black pepper and a touch of salt. Refrigerate until ready to serve.
(This can be made in advace and stored in the refrigerator for up to 3 days.)
3. Preheat the broiler.
4. Brush the salmon fillets with canola oil, season them with salt and pepper and place them on a nonstick baking sheet.
5. Broil the fillets until they are just cooked through, about 3 to 4 minutes per side.
6. Serve each salmon fillet, hot or at room temperature, with a dollop of horseradish sauce and a serving of cucumber salad.Serving Size: 1 fillet with sauce and salad