COOK spaghetti in a large pot of boiling water, following package directions but omitting salt, until tender, 7 to 8 min. Drain and return pasta to pot.
HEAT a very large non-stick frying pan over medium-high. Add olive oil, then minced garlic, carrots, celery and onion. Cook until carrots begin to soften, 4 to 5 min. Stir in red wine and water, vegetable broth and tomato paste. Add green lentils. Boil until most of the liquid has evaporated but mixture is still saucy, about 15 min. Stir in parmesan until sauce is thickened.
ADD half of bolognese sauce (about 3 1/2 cups) to pasta. Stir to coat. Divide among 4 plates. Sprinkle with parmesan and chopped basil. Reserve remaining half of bolognese for Lentil Ragu over Polenta.