Combine beef, bread crumbs, 1/3 C dressing and onion. Mix lightly. Don't over mix. Shape into patties and grill or broil until brown on both sides. Brush bread with dressing; sprinkle with oregano, and grill or broil until lightly browned on both sides.
Top slices of toast with meat patty. Serve with a green salad and sliced tomatoes.