Turkey Tetrazzini

5 tablespoons butter or margarine

1/2 cup chopped onion (1 medium)

1 bell pepper, chopped

1 package (8 oz) fresh button mushrooms, quartered

1/3 cup dry sherry

2 containers (10 oz each) refrigerated reduced-fat Alfredo pasta sauce

1/2 cup plus 2 tablespoons finely shredded Parmesan cheese

3 cups cut-up cooked turkey

1/2 cup bread crumbs

1/2 cup sliced almonds