Place butter in a 1 quart casserole. Microwave at high (100%) until melted, 30 to 45 seconds. Stir in flour. Blend in milk, onion, celery salt, salt and pepper. Micrwave at medium high (70%) untij slightjy thickened, 3 to4 minutes, stirring twice during cooking time.
Stir in pimento and lima beans.Spnnkle bread crumbs over top. Microwave at medium high (70%) until heated, 4 to 5 minutes. Makes 4 servings.