“Carrots and pasta don’t hang out together enough, considering how well they get along,” says plant-based food writer Richard Makin. Place the sliced carrots and onion in a large baking tray and drizzle with half of the olive oil. Reserving around a cup of the pasta water, drain and return the pasta to the pan. Pour the creamy sauce over the pasta and place the saucepan back over medium heat. If necessary, use the reserved pasta water to loosen the sauce.