Still a lot of pasta, which predates the Columbian exchange. But probably a lot more focus on herbal seasonings, cheese/dairy, oils, etc. Carbonara probably still popular. A lot more pesto on average.

Pizza would be white pizza with toppings, maybe with a pesto base. Fish, meat dishes, and European vegetable dishes probably still mostly untouched.

You’re really just missing tomato sauces and gnocchi with the lack of the Columbian exchange, and tomato is essentially optional in many Italian dishes anyways. Surprisingly not as big a change as I would have thought.

I think maybe in North America we associate tomatoes more strongly with Italian food because it was more readily available for Italian-American immigrants than it was back in Italy.