Portabella Mushroom Sandwiches

Why I Love This Recipe
Ingredients You'll Need
20 slices (each 3/4-inch thick) Portabella mushroom (about 4 medium-large)
Nonstick olive oil cooking spray
1/8 teaspoon salt
1/8 teaspoon coarsely ground black pepper
1/2 teaspoon dried fines herbes* or dried Italian seasoning
4 sourdough rolls, onion rolls, or multigrain burger buns (2 ounces each)
4 ounces sliced nonfat or reduced-fat mozzarella or provolone cheese
TOPPINGS
1/4 cup nonfat or reduced-fat mayonnaise
4 teaspoons Dijon mustard
4 slices red onion
4 slices tomato
12 fresh tender spinach or arugula leaves
Directions
Coat a large baking sheet with nonstick olive oil cooking spray, and arrange the mushrooms in a single layer on the sheet. Spray the tops of the mushrooms lightly with the cooking spray, and sprinkle with the salt, pepper, and herbs.
Bake uncovered at 450°F for 10 minutes. Turn the slices, and bake for 5 additional minutes, or until tender and nicely browned. Remove the mushrooms from the oven, and set aside.
While the mushrooms are cooking, place the mayonnaise and mustard in a small bowl, and stir to mix well. Set aside.
Split the rolls in half lengthwise, and arrange the halves on a large baking sheet, cut sides up. Place under a preheated broiler, and broil for a minute or 2, or until lightly toasted. Spread each of the cut sides with some of the mayonnaise mixture. Set the roll tops aside, leaving the bottoms on the baking sheet.
Place first a quarter of the mushroom slices and then a quarter of the cheese over the bottom half of each roll. Return to the broiler for about 1 minute, or until the cheese is melted.
Top the melted cheese on each roll with a slice of onion, a slice of tomato, 3 spinach or arugula leaves, and a roll half. Serve hot.