PORTOBELLO BURGERS WITH RED PEPPER MAYONNAISE

Portobello Burgers with Red Pepper Mayonnaise image

Yield Makes 4 servings

Number Of Ingredients 10

1/2 cup chopped drained roasted red peppers from jar
1/4 cup low-fat mayonnaise
1 garlic clove, chopped
1/8 teaspoon cayenne pepper
Nonstick vegetable oil spray
4 large portobello mushrooms, stems removed
4 1/2-inch-thick red onion slices
4 1/2-inch-thick crusty country bread slices (each about 5x3 inches)
2 tablespoons rice vinegar
4 cups baby spinach leaves

Steps:

Blend first 4 ingredients in processor until smooth. Season with salt and pepper.
Spray grill with oil spray; prepare barbecue (medium heat). Spray mushrooms and onion slices with oil spray; sprinkle with salt and pepper. Grill mushrooms, onion and bread until vegetables are tender and bread is golden, turning often, about 12 minutes for vegetables and 5 minutes for bread.
Transfer 2 tablespoons red pepper mayonnaise to large bowl. Whisk in vinegar, add spinach and toss. Divide among 4 plates. Place 1 bread slice atop spinach on each. Top each with 1 mushroom, then 1 onion slice. Spoon 2 tablespoons red pepper mayonnaise atop each.