Cut bread diagonally in 1 -inch slices, leaving bottom crust intact.
Place on sheet of waxed paper large enough to wrap loaf.
Spread dressing between slices and over top of loaf.
Sprinkle generously with parmesan cheese.
Bring sides of paper up over top of loaf.
Twist ends to close loosely.
Microwave 45 seconds on HIGH, or until bread is warm.