In lasagne alla bolognese ragù, carrots are listed with onions and celery.
The three vegetables form the classic aromatic base known in Italian cooking as soffritto. For a Bolognese-style ragù, finely chopped onion, carrot, and celery are gently cooked, traditionally with butter or another cooking fat, before the meat and remaining ingredients are added. Their purpose is to build a savory, rounded foundation rather than to make the sauce taste like a vegetable stew.
The ragù is then combined with other ingredients that vary by recipe and period, including finely ground pork and beef, tomatoes, and sometimes milk or wine. In lasagne alla bolognese, the ragù is layered with pasta sheets, béchamel, and Parmesan cheese.
Peas, eggplant, and zucchini can appear in other lasagna recipes, but they are not the vegetable named in this standard description of Bolognese ragù. Another common misconception is that “Bolognese” simply means any tomato-and-ground-beef sauce; the traditional sauce has a more specific regional structure and a carefully developed aromatic base.