Bring water to a boil in a saucepan. Add lentils and rice; return to a boil. Cover, reduce heat, and simmer 25 minutes or until rice is tender and liquid is almost absorbed. Remove from heat, and let stand 5 minutes or until liquid is absorbed.
Coat a large nonstick skillet with cooking spray; add oil, and place over medium-high heat. Add onion and peppers; sauté 2 minutes or until lightly browned. Reduce to medium-high heat; add mushrooms and garlic; sauté 4 minutes or until tender.
Add vegetables and remaining ingredients to lentils and rice. Let stand 15 minutes for flavors to blend.