Salmon with Horseradish Pistachio Crust

Preheat oven to 350°. Place salmon, skin side down, in an ungreased 15x10x1-in. baking pan. Spread sour cream over each fillet. Combine remaining ingredients. Pat crumb-nut mixture onto tops of salmon fillets, pressing to help coating adhere. Bake until fish just begins to flake easily with a fork, 12-15 minutes.