Tuna Noodle Casserole

4 1/2 tablespoons unsalted butter

10 oz mushroom s, trimmed and sliced

1/4 inch thick (4 cups)

2 teaspoons soy sauce

1/4 cup Sherry

1/4 cup all-purpose flour

2 cups low-sodium chicken broth

1 cup whole milk

2 teaspoons fresh lemon juice

1/4 teaspoon salt

1 (6-oz) can tuna in olive oil , drained

6 oz dried curly egg noodles (preferably Pennsylvania Dutch style; about 3 1/4 cups)

1 1/2 cups coarse fresh bread crumbs (from 3 slices firm white sandwich bread)

4 oz coarsely grated Cheddar (1 cup)

1 tablespoon vegetable oil