Sauté onions and mushrooms. Spray a 9x13-inch (23x33-cm) pan; cover bottom of pan with about ½ cup (125 mL) of Hollandaise sauce.
Layer as follows:
½ cooked lasagna noodles?½ cooked chicken (sprinkled with pepper)?½ sautéed onion-mushroom mixture
Drizzle with half the remaining Hollandaise. Sprinkle with ½ tsp (2.5 mL) each of the basil and oregano. Spread half the asparagus spears on top, then half of each cheese. Repeat these layers, ending with the cheese. Bake, uncovered, at 350ºF (180ºC) for about 35 minutes. Allow lasagna to set 10 minutes before cutting to serve. Makes 8-12 servings.