Portobello Burgers with Red Pepper Mayonnaise

Ingredients

• 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

Instructions

1. Blend first 4 ingredients in processor until smooth.
2. Season with salt and pepper.
3. Spray grill with oil spray; prepare barbecue (medium heat).
4. Spray mushrooms and onion slices with oil spray; sprinkle with salt and pepper.
5. 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.
6. Transfer 2 tablespoons red pepper mayonnaise to large bowl.
7. Whisk in vinegar, add spinach and toss.
8. Divide among 4 plates.
9. Place 1 bread slice atop spinach on each.
10. Top each with 1 mushroom, then 1 onion slice.
11. Spoon 2 tablespoons red pepper mayonnaise atop each.