In saucepan, whisk butter and flour over medium-high until bubbly, 2 minutes. Add half-and-half; whisk until thickened, 2 minutes. Whisk in cheese and nutmeg; season. In 2-quart baking dish, top artichokes with sauce then panko. Bake at 375 degrees , 15 minutes, then broil until golden, 5 minutes. Top with parsley; serve with toasts.