Portobello Burgers

Ingredients

• 1/4 cup low-sodium soy sauce
• 1/4 cup balsamic vinegar
• 2 tablespoons olive oil
• 3 garlic cloves, minced
• 4 (4-inch) portobello mushroom caps
• 1 small red bell pepper
• Cooking spray
• 1/4 cup low-fat mayonnaise
• 1/2 teaspoon olive oil
• 1/8 teaspoon ground red pepper
• 4 (2-ounce) onion sandwich buns
• 4 (1/4-inch-thick) slices tomato
• 4 curly leaf lettuce leaves

Preparation

1. Combine first 4 ingredients in a large zip-top plastic bag; add mushrooms to bag. Seal and marinate at room temperature for 2 hours, turning bag occasionally. Remove mushrooms from bag; discard marinade.
2. Prepare grill to medium heat.
3. Cut bell pepper in half lengthwise; discard seeds and membranes. Place pepper halves on grill rack coated with cooking spray; grill 15 minutes or until blackened, turning occasionally. Place in a zip-top plastic bag; seal. Let stand 10 minutes. Peel. Reserve 1 pepper half for another use. Finely chop 1 pepper half; place in a small bowl. Add mayonnaise, 1/2 teaspoon oil, and ground red pepper; stir well.
4. Place mushrooms, gill sides down, on grill rack coated with cooking spray; grill 4 minutes on each side. Place buns, cut sides down, on grill rack coated with cooking spray; grill 30 seconds on each side or until toasted. Spread 2 tablespoons mayonnaise mixture on top half of each bun. Place 1 mushroom on bottom half of each bun. Top each mushroom with 1 tomato slice and 1 lettuce leaf; cover with top halves of buns.