Prepare one envelope pesto sauce mix according to package directions; set aside. Sprinkle fillets with remaining pesto mix, patting to help adhere.
In a large skillet, heat oil over medium heat. Add fillets; cook until fish just begins to flake easily with a fork, 4-5 minutes on each side. Remove from heat. Sprinkle with cheese and pine nuts. Serve with pesto sauce.
To toast nuts, bake in a shallow pan in a 350° oven for 5-10 minutes or cook in a skillet over low heat until lightly browned, stirring occasionally.