Preheat oven to 350º. Melt butter; add chopped onion & walleye. Cook 5 min. Use spatula to flake fish; stir onion & butter together. Set aside. In large bowl mix cream cheese, mayo & cheese. Add hot sauce, chives, parsley, lemon juice, & paprika. Stir well. Press cream mixture into pie pan/baking dish. Press walleye flakes on top; add cooked onions. Top with breadcrumbs, Parmesan, & a sprinkle of paprika. Bake at 350º for 25 min. or until hot & bubbling.