Place potatoes, 1/2 cup water, and 1 teaspoon salt h a pan. Cover, cook to boiling. Lower heat and cool for 10 minutes. Drain. Melt butter, blend in flour, salt, and pepper. Add mil} and cook, stirring constantly, until thick and smooth. Stir in pimiento, onions, cheese and potatoes. Turn mixture into a casserole and top with crumbs. Bake at 350 F. for 30 minutes. SCALLOPED POTATOES WITH CHEESE 3 tablespoons unsalted butter 1/4 cup all-purpose flour 2 cups chicken broth 1-1/2 cups coarsely grated extra-sharp Cheddar cheese 2 pounds boiling potatoes 1/2 cup fresh bread crumbs Preheat oven to 350 F. and butter a 2-quart shallow baking dish. In a heavy saucepan melt butter over moderately low heat and whisk in flour. Cook roux, whisking, 3 minutes and add broth in a stream, whisking. Bring sauce to a boil, whisking, and simmer, whisking, until thickened, about 2 minutes. Remove pan from heat and whisk in cheese and salt and pepper to taste, whisking until cheese is melted. Peel potatoes and slice about 1/8 inch thick. In prepared baking dish make 5 layers each of potatoes and sauce, beginning with potatoes and ending with sauce. Scalloped potatoes may be prepared up to this point 2 hours ahead and kept covered . Sprinkle bread crumbs on top and bake, uncovered, in oven 1 hour, or until potatoes are tender and top is golden. Serves 4 to 6.