- Thoroughly blend oil and less sodium soy sauce; remove and reserve 1/4 cup.
- Pour remaining mixture over onion and parsley in small bowl; stir to coat all pieces well. Let stand 15 minutes, stirring occasionally.
- Meanwhile, cut bread into 12 slices, each 1/2 inch thick. Lightly brush both sides of bread with reserved soy sauce mixture; place on large baking sheet. Broil 1 to 2 minutes on each side, or until golden.
- Drain onion mixture. Cover each bread slice with roast beef and then onion mixture.
- Sprinkle cheese evenly over onion mixture; serve immediately.