Heat oil in 4-quart saucepot over medium heat and cook carrots with celery, stirring occasionally, until crisp-tender, about 5 minutes. Stir in lentils and cook until golden, about 2 minutes. Stir in garlic and cook 30 seconds.
Stir in tomato sauce, 4 cups water and 1 tablespoon Knorr® Chicken flavor Bouillon. Bring to boil over high heat. Reduce heat to low and simmer covered, stirring occasionally, until lentils are almost done, about 20 minutes.
Stir in macaroni, remaining 1 tablespoon Bouillon and remaining 1 cup water. Simmer covered until lentils and macaroni are tender, about 15 minutes.