1 Medium Onion Per Serving 1 Slice Cheese Per Serving 1 Round Buttered Toast Per Serving Butter for Frying Mustard Seasoning | Peel and slice onions thickly and fry lightly in butter. Arrange on rounds of buttered toast. Season well, place a slice of cheese on top, spread with mustard and place under grill until cheese bubbles. Serve at once. |