Prep smoker by soaking wood chips ahead of time and preheating according to manufactures directions.

Slice a pocket in each salmon fillet and stuff with smoked salmon and dill. Squeeze lemon juice over each portion and season with salt and pepper.

Place the salmon, skin side down, in the smoker and cook for 30 minutes, or until fish is cooked through and begins to flake.

Meanwhile, make the horseradish cream by combining the sour cream, scallion, and horseradish in a small bowl until combined.