Heat olive oil in a large saucepan over medium heat. Add the onion, carrots, celery, and bell pepper. Cook, stirring occasionally, until the vegetables are softened, about 10 minutes.
Stir in the garlic and cook for another 2 minutes, until fragrant.
Add the lentils, crushed tomatoes, tomato paste, oregano, basil, salt, and pepper. Mix well to combine.
Pour in the vegetable broth and add the bay leaf. Bring the mixture to a boil, then reduce the heat and simmer, covered, for about 30 minutes, or until the lentils are tender. If using, add the red wine during the last 10 minutes of cooking.
While the sauce cooks, prepare the pasta according to package instructions.
Remove the bay leaf from the sauce and adjust seasoning if necessary.
Serve the hot Bolognese sauce over the cooked pasta, garnished with fresh basil.