tablespoon plus 1 teaspoon salt, divided
pounds fresh green beans, trimmed
⁄3 cup all-purpose flour
cups skim milk
cup grated Parmesan cheese
tablespoon lemon zest
cup panko (Japanese bread crumbs)
Preheat oven to 400°. Spray a 13x9-inch baking dish with nonstick cooking spray. In a large Dutch oven, bring 8 cups water to a boil. Add 1 tablespoon salt. Add beans, and cook until tender, about 4 to 5 minutes; drain. In a large saucepan over medium-high heat, melt butter. Add flour, stirring constantly with a whisk. Gradually add milk, stirring constantly until smooth. Add cheese, lemon zest, and remaining 1 teaspoon salt. Stir in green beans, and pour into prepared pan. Sprinkle top with panko. Bake until golden, about 15 minutes.