Combine rice and 2 1/4 cups water in a saucepan; bring to a boil. Cover, reduce heat, and simmer 45 minutes or until liquid is absorbed. Let stand 10 minutes.
Combine 6 cups water and lentils in a large saucepan; bring to a boil. Cover, reduce heat, and simmer 20 minutes or until tender. Drain, reserving 1 cup cooking liquid.
Preheat oven to 400°.
Heat oil in a nonstick skillet coated with cooking spray over medium-high heat. Add carrot and mushrooms; sauté 6 minutes or until mushrooms are lightly browned.
Combine lentils, reserved cooking liquid, mushroom mixture, tomatoes, and next 5 ingredients. Spoon mixture into a 2-quart baking dish coated with cooking spray. Cover and bake at 400° for 30 minutes or until bubbly. Remove bay leaf. Spoon lentil mixture over rice; sprinkle with cheese.