PORTOBELLO "STEAK" BURGER WITH CARAMELIZED ONIONS 1 cup balsamic vinegar 2 tablespoons olive oil 1 teaspoon dried basil 1/4 teaspoon kosher salt 1/4 teaspoon ground white pepper 2 garlic cloves, minced 6 portobello mushroom caps (about 1 1/2 pounds) Cooking spray 1 tablespoon olive oil 1 1/2 cups sliced onion 1/4 cup low-fat mayonnaise 1 teaspoon bottled minced roasted garlic 6 (2-ounce) whole-wheat Kaiser rolls or hamburger buns 6 curly leaf lettuce leaves 6 large (1/4-inch-thick) slices tomato

Combine first 6 ingredients in a large zip-top plastic bag. Add mushroom caps, seal and marinate in refrigerator 24 hours.

Prepare grill or broiler.

Remove mushroom caps from bag; discarding marinade. Place mushroom caps on grill rack or broiler pan coated with cooking spray; cook 5 minutes or until tender.

Heat the oil in a medium nonstick skillet over medium-high heat. Add onion; cover and cook 10 minutes or until golden brown, stirring frequently.

Combine mayonnaise and roasted garlic in a small bowl. Spread 1/2 tablespoon mayonnaise mixture evenly over the top halves of buns; top each bottom half of bun with 1 lettuce leaf, 1 tomato slice, 1 mushroom cap, 1 tablespoon caramelized onion, and top half of bun.

6 servings.

1 Serving: Calories: 274 (Cal. from fat: 30%), Fat: 9.3g (Saturated: 1.4g), Cholesterol: 3mg, Sodium: 420mg, Carbohydrate: 40.4g, Protein: 8.9g.

[Cooking Light, March 2001]