PREPARATION:
- Place lentils in medium saucepan; cover with 1 inch water. Bring to a boil; reduce heat to low. Simmer, covered, 25 to 35 minutes until tender. Rinse; drain and set aside. Meanwhile, cook rice according to package directions; set aside.
- Heat oil in heavy, large skillet over medium heat. Add mushrooms and chopped onion. Cook and stir 20 to 25 minutes until mushrooms are brown. Combine mushroom mixture, cheese, walnuts, lentils, rice, cilantro, eggs and pepper in large bowl; mix well. Cover; chill.
- Preheat broiler. Grease 15X10-inch jelly-roll pan with oil. Shape lentil mixture into 6 (1/2-inch-thick) patties. Arrange patties on prepared pan. Broil, 4 inches from heat, 3 to 4 minutes on each side or until golden brown, turning once. Serve on buns with mayonnaise, red onion, lettuce and tomatoes.
