Tuna Casserole Supreme

1/2 cup water
1 teaspoons chicken bouillon granules
1 package (10 ounces) frozen green beans
1 cup chopped onions
1 cup sliced fresh mushrooms
1/4 cup chopped celery
1 garlic clove, minced
1/2 teaspoon dill weed
1/2 teaspoon salt
1/8 teaspoon pepper
4 teaspoons cornstarch
1 1/2 cups milk
1/2 cup shredded Swiss cheese
1/4 cup mayonnaise
2-1/2 cups medium noodles, cooked and drained
1 can (12.25 ounce) tuna, drained and flaked
1/3 cup dry bread crumbs
1 Tablespoon butter or margarine

In a large saucepan, bring water and bouillon to a boil, stirring to dissolve. Add the next eight ingredients; bring to a boil. Reduce heat; cover and simmer 5 minutes until vegetables are tender. Dissolve cornstarch in milk; add to vegetable mixture, stirring constantly. Bring to a boil; boil 2 minutes or until thickened. Remove from the heat; stir in cheese and mayonnaise until cheese is melted. Fold in noodles and tuna. Pour into a greased 2-1/2 quart baking dish. Brown bread crumbs in butter; sprinkle on top of casserole. Bake, uncovered, at 350 degrees for 25-30 minutes or until heated through.