Preheat oven to 350.

Cook and drain pasta al dente according to package instructions.

In 1 1/2 quart saucepan, melt 2 tbsp butter over low heat. Stir in flour and salt. Cool over medium heat, stirring constantly, until smooth and bubbly; remove from heat. Stir in milk. Heating to boil, stirring constantly. Boil and stir one minute. Stir in cheese until melted.

Stir in pasta, vegetables and drained canned fish; mix well. Spoon into ungreased 2-quart casserole. Cover and bake about 25 minutes or until hot and bubbly.

In small bowl mix bread crumbs and 1 tbsp melted butter. Sprinkle over casserole. Bake uncovered about 5 minutes longer or until topping is toasted.